Method for removing radioactive cesium, hydrophilic resin composition for removal of radioactive cesium, method for removing radioactive iodine and radioactive cesium, and hydrophilic resin composition for removal of radioactive iodine and radioactive cesium

ABSTRACT

A method for removing radioactive cesium and/or iodine from a radioactive substance in liquid and/or a solid matter using a hydrophilic resin composition comprising a hydrophilic resin and a metal ferrocyanide compound, wherein the hydrophilic resin includes at least one hydrophilic resin selected from the group consisting of a hydrophilic polyurethane resin, a hydrophilic polyurea resin, and a hydrophilic polyurethane-polyurea resin each having at least a hydrophilic segment, and a metal ferrocyanide compound is dispersed in the hydrophilic resin composition in a ratio of at least 1 to 200 mass parts relative to 100 mass parts of the hydrophilic resin.

TECHNICAL FIELD

The present invention relates to a method for removing radioactivecesium present in liquid and/or a solid matter generated from a nuclearpower plant or a reprocessing facility of spent nuclear fuel and to ahydrophilic resin composition suitable for the method, the hydrophilicresin composition exhibiting a function immobilizing radioactive cesium.The present invention also relates to a method capable of applyingremoving processing to both of radioactive iodine and radioactive cesiumpresent in liquid and/or a solid matter generated from a nuclear powerplant or a reprocessing facility of spent nuclear fuel and to ahydrophilic resin composition suitable for the method, the hydrophilicresin composition exhibiting a function immobilizing both of radioactiveiodine and radioactive cesium.

BACKGROUND ART

In currently widespread nuclear reactor power plants, nuclear fission ina nuclear reactor is accompanied by generation of a considerable amountof radioactive by-products. The main radioactive substances among theradioactive by-products are fission products and active elementsincluding extremely dangerous radioactive isotopes such as radioactiveiodine, radioactive cesium, radioactive strontium, and radioactivecerium. Since radioactive iodine among these radioactive substancesturns into a gas at 184° C., there is a risk that the radioactive iodineis extremely liable to be discharged at the time of inspection orexchange of fuel and furthermore by an unforeseen event such as anaccident during handling fuel or a reactor excursion accident. The majorradioactive iodine isotopes to be taken into account at the time ofdischarge are iodine 129 having a long half-life (half-life: 1.57×10⁷years) and iodine 131 having a short half-life (half-life: 8.05 days).Here, ordinary iodine that does not have radioactivity is an essentialtrace element in the human body, is collected in the thyroid gland nearthe throat, and becomes a component of a growth hormone. Therefore, whena human takes in radioactive iodine through breathing or water/foods,the radioactive iodine is collected in the thyroid gland in the same wayas in the case of ordinary iodine and increases internal exposure toradioactivity, and accordingly, a particularly strict measure forreducing the amount of radioactivity to be discharged must beimplemented with regard to radioactive iodine.

Moreover, radioactive cesium has a melting point of 28.4° C., is one ofmetals that become liquid at around a normal temperature, and is a metalthat is extremely liable to be discharged as well as radioactive iodine.The major radioactive cesium isotopes to be taken into account at thetime of discharge are cesium 134 having a relatively short half-life(half-life: 2 years) and cesium 137 having a long half-life (half-life:30 years). Among the major radioactive cesium isotopes, cesium 137 notonly has a long half-life but also emits high-energy radiation, and hasa property that water solubility is high because the radioactive cesiumis an alkaline metal. Furthermore, radioactive cesium is easily absorbedin the human body through breathing and also through skin and isuniformly dispersed in the whole body, and therefore a health hazard tohumans when the radioactive cesium is discharged becomes serious.

Thus, when radioactive cesium is accidentally discharged due to anunforeseen event or the like from nuclear reactors in operation all overthe world, there are concerns that the radioactive cesium causes notonly radioactive contamination to workers at nuclear reactors orneighborhood residents but also radioactive contamination over a widerrange to humans and animals through foods or water contaminated by theradioactive cesium carried by air. The danger with regard to theradioactive contamination has already been proven undoubtedly by theaccident in Chernobyl nuclear power plant.

To such a situation, a cleaning processing system, a physical/chemicalprocessing system by solid adsorbent filling using fibrous activatedcarbon or the like (see Patent Literatures 1 and 2), processing by anion exchange material (see Patent Literature 3), and so on have beenstudied as a method for processing radioactive iodine generated in anuclear reactor.

However, any of the above methods has problems as described below, andthe development of a method for removing radioactive iodine in whichthese problems are solved is desired. First of all, an alkaline cleaningmethod or the like exists as a cleaning processing system practicallyused, however there are lots of problems in terms of quantity and safetyto apply processing by the cleaning processing system with a liquidadsorbent and store the processed liquid as it is for a long period oftime. Moreover, in the physical/chemical processing system by solidadsorbent filling, captured radioactive iodine is always facing thepossibility of being replaced with other gases, and moreover theprocessing system has a problem that an adsorbed matter is liable to bedischarged when the temperature increases. Furthermore, in theprocessing system by an ion exchange material, the heat resistanttemperature of the ion exchange material is up to about 100° C. andthere is a problem that the ion exchange material cannot exhibitsufficient performance at a temperature higher than the heat resistanttemperature.

On the other hand, as a method for applying removing processing toradioactive cesium generated by nuclear fission in a nuclear reactor, anadsorption method with an inorganic ion exchanger or a selective ionexchange resin, a coprecipitation method by using a heavy metal and asoluble ferrocyanide or ferrocyanide salt together, a chemicalprocessing method with a cesium precipitation reagent, and so on areknown (see, for example, Patent Literature 4).

However, in any of the above-described processing methods, large scalefacilities such as a circulation pump, a cleaning tank, and furthermorea filling tank containing various adsorbents are necessary, and inaddition, a large amount of energy is needed to operate thesefacilities. Moreover, when supply of the power source is suspended as inthe accident occurred at the Fukushima No. 1 nuclear power plant inJapan on Mar. 11, 2011, these facilities cannot be operated and thedegree of contamination risk by radioactive cesium in particularincreases. Especially in the case where the supply of the power sourceis suspended, applying a method for removing radioactive cesium diffusedinto peripheral areas falls into an extremely difficult situation, andit is concerned that a situation in which radioactive contaminationexpands may occur. Accordingly, there is an urgent need to develop amethod for removing radioactive cesium that is applicable even when thesituation in which the supply of the power source is suspended occurs,and when such method for removing radioactive cesium is developed, themethod is extremely useful.

CITATION LIST Patent Literature

-   Patent Literature 1: JP-62-44239-   Patent Literature 2: JP-A-2008-116280-   Patent Literature 3: JP-A-2005-37133-   Patent Literature 4: JP-A-4-118596

SUMMARY OF INVENTION Technical Problem

Accordingly, an object of the first present invention and the secondpresent invention is to solve the problems of conventional arts and toprovide a novel method for removing radioactive cesium that is simpleand low-cost, furthermore does not require an energy source such aselectricity, moreover can take in and stably immobilize the removedradioactive cesium within a solid, and is capable of reducing the volumeof radioactive waste as necessary. Moreover, another object of the firstpresent invention and the second present invention is to provide a novelhydrophilic resin composition that has a function useful for theabove-described method and capable of immobilizing radioactive cesium,the hydrophilic resin composition capable of realizing applying removingprocessing to radioactive cesium simply.

Furthermore, yet another object of the second present invention is toprovide a novel hydrophilic resin composition more excellent inpractical use by which hydrophilic resin composition the waterresistance and the blocking resistance performance (sticking resistance)of the surface are improved in the case where the hydrophilic resincomposition is used in a form such as a resin film or sheet in applyingprocessing in addition to having a function particularly useful for theabove-described method and capable of immobilizing radioactive cesium.

Moreover, an object of the third present invention and the fourthpresent invention is, in providing an effective processing methodcapable of applying processing to radioactive iodine and radioactivecesium together, to solve the problems of conventional arts and toprovide a novel method for removing radioactive iodine and radioactivecesium that is simple and low-cost, furthermore does not require anenergy source such as electricity, moreover can take in and stablyimmobilize the removed radioactive iodine and radioactive cesium withina solid, and is capable of reducing the volume of radioactive waste asnecessary. Moreover, another object of the third present invention andthe fourth present invention is to provide a novel hydrophilic resincomposition that has a function useful in carrying out theabove-described method and capable of immobilizing both of radioactiveiodine and radioactive cesium, the hydrophilic resin composition capableof applying removing processing to these radioactive substancestogether.

Furthermore, yet another object of the fourth present invention is toprovide a novel hydrophilic resin composition more excellent inpractical use by which hydrophilic resin composition the waterresistance and the blocking resistance performance (sticking resistance)of the surface are improved in the case where the hydrophilic resincomposition is used in a form such as a resin film or sheet in applyingprocessing in addition to having a function particularly useful for theabove-described method and capable of immobilizing radioactive iodineand radioactive cesium.

Solution to Problem

Each of the objects is achieved by the first, the second, the third, orthe fourth present invention described below. Namely, as the firstpresent invention, provided is a method for removing radioactive cesiumapplying removing processing to radioactive cesium in a radioactivewaste liquid and/or a radioactive solid matter using a hydrophilic resincomposition comprising a hydrophilic resin and a metal ferrocyanidecompound, wherein the hydrophilic resin composition comprises at leastone hydrophilic resin selected from the group consisting of ahydrophilic polyurethane resin, a hydrophilic polyurea resin, and ahydrophilic polyurethane-polyurea resin each having a hydrophilicsegment; and the metal ferrocyanide compound is dispersed in thehydrophilic resin composition in a ratio of at least 1 to 200 mass partsrelative to 100 mass parts of the hydrophilic resin.

As the second present invention, provided is a method for removingradioactive cesium applying removing processing to radioactive cesiumpresent in a radioactive waste liquid and/or a radioactive solid matterusing a hydrophilic resin composition comprising a hydrophilic resin anda metal ferrocyanide compound, wherein the hydrophilic resin comprisesat least one selected from the group consisting of a hydrophilicpolyurethane resin, a hydrophilic polyurea resin, and a hydrophilicpolyurethane-polyurea resin each having a hydrophilic segment andfurther each having, in the main chain and/or a side chain in thestructure thereof, a polysiloxane segment; and the hydrophilic resincomposition comprises the metal ferrocyanide compound dispersed thereinin a ratio of at least 1 to 200 mass parts relative to 100 mass parts ofthe hydrophilic resin.

As another embodiment in the first present invention, provided is ahydrophilic resin composition for removing radioactive cesium exhibitinga function capable of immobilizing radioactive cesium in liquid and/or asolid matter, wherein the hydrophilic resin composition comprises ahydrophilic resin and a metal ferrocyanide compound; the hydrophilicresin is at least one resin selected from the group consisting of ahydrophilic polyurethane resin, a hydrophilic polyurea resin, and ahydrophilic polyurethane-polyurea resin each having a hydrophilicsegment and each obtained by reacting an organic polyisocyanate with ahigh-molecular weight hydrophilic polyol and/or polyamine being ahydrophilic component, the resin being insoluble to water and hot water;and the metal ferrocyanide compound is dispersed in the hydrophilicresin composition in a ratio of at least 1 to 200 mass parts relative to100 mass parts of the hydrophilic resin.

As another embodiment in the second present invention, provided is ahydrophilic resin composition for removing radioactive cesium exhibitinga function capable of immobilizing radioactive cesium in liquid and/or asolid matter, wherein the hydrophilic resin composition comprises ahydrophilic resin and a metal ferrocyanide compound; the hydrophilicresin is a resin having a hydrophilic segment and a polysiloxane segmentand obtained by reacting, as a part of a raw material, a compound havingat least one active hydrogen-containing group and a polysiloxane segmentin the same molecule, the resin being insoluble to water and hot water;and the metal ferrocyanide compound is dispersed in the hydrophilicresin composition in a ratio of at least 1 to 200 mass parts relative to100 mass parts of the hydrophilic resin.

As yet another embodiment in the second present invention, provided is ahydrophilic resin composition for removing radioactive cesium exhibitinga function capable of immobilizing radioactive cesium in liquid and/or asolid matter, wherein the hydrophilic resin composition comprises ahydrophilic resin and a metal ferrocyanide compound; the hydrophilicresin is at least one selected from the group consisting of ahydrophilic polyurethane resin, a hydrophilic polyurea resin, and ahydrophilic polyurethane-polyurea resin each having a hydrophilicsegment, further each having, in the main chain and/or a side chain inthe structure thereof, a polysiloxane segment, and each obtained byreacting an organic polyisocyanate, a high molecular weight polyoland/or polyamine being a hydrophilic component, and a compound having atleast one active hydrogen-containing group and a polysiloxane segment inthe same molecule; and the metal ferrocyanide compound is dispersed inthe hydrophilic resin composition in a ratio of at least 1 to 200 massparts relative to 100 mass parts of the hydrophilic resin.

Preferable embodiments of the first or the second present inventionrelating to the above-described method for removing radioactive cesiumor the above-described hydrophilic resin composition include that thehydrophilic segment is a polyethylene oxide segment; and that the metalferrocyanide compound is a compound represented by the following generalformula (1).

A_(x)M_(y)[Fe(CN)₆]  (1)

[In the formula, A is any one selected from K, Na, and NH₄, M is any oneselected from Ca, Mn, Fe, Co, Ni, Cu, and Zn, x and y satisfy anequation x+ny=4 (x is an integer from 0 to 3), and n represents avalence number of M]

As the third present invention, provided is a method for removingradioactive iodine and radioactive cesium applying removing processingto both of radioactive iodine and radioactive cesium present in aradioactive waste liquid and/or a radioactive solid matter using ahydrophilic resin composition comprising a hydrophilic resin and a metalferrocyanide compound, wherein the hydrophilic resin comprises at leastone selected from the group consisting of a hydrophilic polyurethaneresin, a hydrophilic polyurea resin, and a hydrophilicpolyurethane-polyurea resin each having a hydrophilic segment andfurther each having, in the main chain and/or a side chain in thestructure thereof, a tertiary amino group; and the hydrophilic resincomposition comprises the metal ferrocyanide compound dispersed thereinin a ratio of at least 1 to 200 mass parts relative to 100 mass parts ofthe hydrophilic resin.

A preferable embodiment of the above described third present inventionincludes that the hydrophilic resin is a resin formed from, as a part ofa raw material, a polyol having at least one tertiary amino group or apolyamine having at least one tertiary amino group.

As the fourth present invention, provided is a method for removingradioactive iodine and radioactive cesium applying removing processingto both of radioactive iodine and radioactive cesium present in aradioactive waste liquid and/or a radioactive solid matter using ahydrophilic resin composition comprising a hydrophilic resin and a metalferrocyanide compound, wherein the hydrophilic resin comprises at leastone selected from the group consisting of a hydrophilic polyurethaneresin, a hydrophilic polyurea resin, and a hydrophilicpolyurethane-polyurea resin each having a hydrophilic segment andfurther each having, in the main chain and/or a side chain in thestructure thereof, a tertiary amino group and a polysiloxane segment;and the hydrophilic resin composition comprises the metal ferrocyanidecompound dispersed therein in a ratio of at least 1 to 200 mass partsrelative to 100 mass parts of the hydrophilic resin.

A preferable embodiment of the above-described fourth present inventionincludes that the hydrophilic resin is formed from, as a part of a rawmaterial, a polyol having at least one tertiary amino group or apolyamine having at least one tertiary amino group and a compound havingat least one active hydrogen-containing group and a polysiloxane segmentin the same molecule.

As another embodiment in the third present invention, provided is ahydrophilic resin composition for removing radioactive iodine andradioactive cesium exhibiting a function capable of immobilizing both ofradioactive iodine and radioactive cesium in liquid and/or a solidmatter, wherein the hydrophilic resin composition comprises ahydrophilic resin and a metal ferrocyanide compound; the hydrophilicresin is a resin having a hydrophilic segment, having, in the molecularchain, a tertiary amino group, and formed from, as a part of a rawmaterial, a polyol having at least one tertiary amino group or apolyamine having at least one tertiary amino group, the resin beinginsoluble to water and hot water; and the metal ferrocyanide compound isdispersed in the hydrophilic resin composition in a ratio of at least 1to 200 mass parts relative to 100 mass parts of the hydrophilic resin.

As yet another embodiment in the third present invention, provided is ahydrophilic resin composition for removing radioactive iodine andradioactive cesium exhibiting a function capable of immobilizing both ofradioactive iodine and radioactive cesium in liquid and/or a solidmatter, wherein the hydrophilic resin composition comprises ahydrophilic resin and a metal ferrocyanide compound; the hydrophilicresin is at least one selected from the group consisting of ahydrophilic polyurethane resin, a hydrophilic polyurea resin, and ahydrophilic polyurethane-polyurea resin each having a hydrophilicsegment, further each having, in the main chain and/or a side chain inthe structure thereof, a tertiary amino group, and each obtained byreacting an organic polyisocyanate, a high molecular weight hydrophilicpolyol and/or polyamine being a hydrophilic component, and a compoundhaving at least one active hydrogen-containing group and at least onetertiary amino group in the same molecule; and the metal ferrocyanidecompound is dispersed in the hydrophilic resin composition in a ratio ofat least 1 to 200 mass parts relative to 100 mass parts of thehydrophilic resin.

As another embodiment in the fourth present invention, provided is ahydrophilic resin composition for removing radioactive iodine andradioactive cesium exhibiting a function capable of immobilizing both ofradioactive iodine and radioactive cesium in liquid and/or a solidmatter, wherein the hydrophilic resin composition comprises ahydrophilic resin and a metal ferrocyanide compound; the hydrophilicresin is a resin having a hydrophilic segment, having, in the molecularchain, a tertiary amino group and a polysiloxane segment, and formedfrom, as a part of a raw material, a polyol having at least one tertiaryamino group or a polyamine having at least one tertiary amino group anda compound having at least one active hydrogen-containing group and apolysiloxane segment in the same molecule, the resin being insoluble towater and hot water; and the metal ferrocyanide compound is dispersed inthe hydrophilic resin composition in a ratio of at least 1 to 200 massparts relative to 100 mass parts of the hydrophilic resin.

As yet another embodiment in the fourth present invention, provided is ahydrophilic resin composition for removing radioactive iodine andradioactive cesium exhibiting a function capable of immobilizing both ofradioactive iodine and radioactive cesium in liquid and/or a solidmatter, wherein the hydrophilic resin composition comprises ahydrophilic resin and a metal ferrocyanide compound; the hydrophilicresin is at least one selected from the group consisting of ahydrophilic polyurethane resin, a hydrophilic polyurea resin, and ahydrophilic polyurethane-polyurea resin each having a hydrophilicsegment, each having, in the main chain and/or a side chain in thestructure thereof, a tertiary amino group and a polysiloxane segment,and each obtained by reacting an organic polyisocyanate, a highmolecular weight hydrophilic polyol and/or polyamine being a hydrophiliccomponent, a compound having at least one active hydrogen-containinggroup and at least one tertiary amino group in the same molecule, and acompound having at least one active hydrogen-containing group and apolysiloxane segment in the same molecule; and the metal ferrocyanidecompound is dispersed in the hydrophilic resin composition in a ratio ofat least 1 to 200 mass parts relative to 100 mass parts of thehydrophilic resin.

Preferable embodiments of the third or the fourth present inventionrelating to the above-described method for removing radioactive cesiumor the above-described hydrophilic resin composition include that thehydrophilic segment is a polyethylene oxide segment; and that the metalferrocyanide compound is a compound represented by the following generalformula (1).

A_(x)M_(y)[Fe(CN)₆]  (1)

[In the formula, A is any one selected from K, Na, and NH₄, M is any oneselected from Ca, Mn, Fe, Co, Ni, Cu, and Zn, x and y satisfy anequation x+ny=4 (x is an integer from 0 to 3), and n represents avalence number of M]

Advantageous Effects of Invention

According to the first present invention or the second presentinvention, provided is a novel method for removing radioactive cesiumthat is capable of applying processing to radioactive cesium present inliquid or a solid matter simply and at low cost, furthermore does notrequire an energy source such as electricity, moreover can take in andstably immobilize the removed radioactive cesium within a solid, and canachieve the volume reduction of radioactive waste as necessary.

According to the first present invention, provided is a novelhydrophilic resin composition that has a function capable ofimmobilizing radioactive cesium, makes it possible to realize applyingremoving processing to radioactive cesium, and can reduce the volume ofradioactive waste as necessary because the main component of thehydrophilic resin composition is a resin composition. Theabove-described remarkable effects are achieved by an extremely simplemethod that utilizes the hydrophilic resin composition comprising ametal ferrocyanide compound a representative example of which isPrussian blue dispersed in a hydrophilic resin having a hydrophilicsegment in the structure thereof. The hydrophilic resin is obtained byreacting, for example, an organic polyisocyanate with a high molecularweight hydrophilic polyol and/or polyamine (hereinafter, each of thepolyol and the polyamine is also referred to as a “hydrophiliccomponent”), and more specifically examples of the hydrophilic resininclude a hydrophilic polyurethane resin, a hydrophilic polyurea resin,and a hydrophilic polyurethane-polyurea resin.

Particularly, according to the second present invention, a hydrophilicresin composition with high practicability that has a function capableof immobilizing radioactive cesium and realizes improvement in the waterresistance and the blocking resistance performance (sticking resistance)of the surface when used in a form such as a film form is provided, andthereby the removing processing of radioactive cesium can be realized ina better state. Furthermore, since the main component of the hydrophilicresin composition is a resin composition, the volume reduction of theradioactive waste becomes possible as necessary. These remarkableeffects in the second present invention are achieved by an extremelysimple method that utilizes a hydrophilic resin composition comprising ametal ferrocyanide compound a representative example of which isPrussian blue dispersed therein together with a hydrophilic resin havinga hydrophilic segment in the structure thereof and having, in the mainchain and/or a side chain, a polysiloxane segment. The hydrophilic resinis obtained by reacting, for example, an organic polyisocyanate, ahydrophilic component, and a compound having at least one activehydrogen-containing group and a polysiloxane segment in the samemolecule, and more specific examples of the hydrophilic resin include ahydrophilic polyurethane, a hydrophilic polyurea, and a hydrophilicpolyurethane-polyurea each having the above-described structure.

According to the third present invention or the fourth presentinvention, provided is a novel method that is capable of applyingremoving processing to radioactive iodine and radioactive cesium presentin liquid or a solid matter simply and at low cost, furthermore does notrequire an energy source such as electricity, moreover can take in andfurther stably immobilize the removed radioactive iodine and the removedradioactive cesium within a solid, can achieve the volume reduction ofradioactive waste as necessary, and can apply removing processing ofradioactive iodine and radioactive cesium together. According to thepresent invention, provide is a novel hydrophilic resin composition thathas a function capable of immobilizing both of radioactive iodine andradioactive cesium, makes it possible to realize applying removingprocessing to radioactive iodine and radioactive cesium together, andcan reduce the volume of radioactive waste as necessary because the maincomponent of the hydrophilic resin composition is a resin composition.

The remarkable effects in the third present invention are achieved by anextremely simple method that utilizes a hydrophilic resin compositionobtained by dispersing Prussian blue in a hydrophilic resin such as ahydrophilic polyurethane resin, a hydrophilic polyurea resin, and ahydrophilic polyurethane-polyurea resin obtained by reacting an organicpolyisocyanate, a hydrophilic component, and a compound having at leastone active hydrogen-containing group and at least one tertiary aminogroup in the same molecule.

Particularly, according to the fourth present invention, a hydrophilicresin composition with high practicability that has a function ofimmobilizing radioactive iodine and radioactive cesium and realizesimprovement in the water resistance and the blocking resistanceperformance (sticking resistance) of the surface when used in a formsuch as a film form is provided, and thereby the removing processing ofradioactive iodine and radioactive cesium can be realized in a betterstate. The remarkable effects in the fourth present invention areachieved by the hydrophilic resin having a hydrophilic segment in thestructure thereof, and having, in the molecular chain, at least onetertiary amino group and a polysiloxane segment, and in more detail, theremarkable effects in the fourth present invention are achieved by anextremely simple method that utilizes a hydrophilic resin compositionobtained by dispersing a metal ferrocyanide compound in a hydrophilicresin such as a hydrophilic polyurethane resin, a hydrophilic polyurearesin, and a hydrophilic polyurethane-polyurea resin obtained byreacting an organic polyisocyanate, a hydrophilic component, a compoundhaving at least one active hydrogen-containing group and at least onetertiary amino group in the same molecule, and a compound having atleast one active hydrogen-containing group and a polysiloxane segment inthe same molecule.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a graph showing the relation between the cesium concentrationin each aqueous solution and the immersion time of each film comprisinga hydrophilic resin composition of Examples 1-1 to 1-3.

FIG. 2 is a graph showing the relation between the cesium concentrationof each aqueous solution and the immersion time of each film comprisinga hydrophilic resin composition of Examples 2-1 to 2-3.

FIG. 3 is a graph showing the relation between the cesium concentrationin each aqueous solution and the immersion time of each film comprisinga non-hydrophilic resin composition of Comparative Examples 1a and 2a.

FIG. 4 is a graph showing the relation between the iodine concentrationof each aqueous solution and the immersion time of each film prepared bya hydrophilic resin composition of Examples 3-1 to 3-3.

FIG. 5 is a graph showing the relation between the cesium concentrationof each aqueous solution and the immersion time of each film prepared bya hydrophilic resin composition of Examples 3-1 to 3-3.

FIG. 6 is a graph showing the relation between the iodine concentrationof each aqueous solution and the immersion time of each film prepared bya hydrophilic resin composition of Examples 4-1 to 4-3.

FIG. 7 is a graph showing the relation between the cesium concentrationof each aqueous solution and the immersion time of each film prepared bya hydrophilic resin composition of Examples 4-1 to 4-3.

FIG. 8 is a graph showing the relation between the iodine concentrationof each aqueous solution and the immersion time of each film prepared bya non-hydrophilic resin composition of Comparative Examples 1b to 2b.

FIG. 9 is a graph showing the relation between the cesium concentrationof each aqueous solution and the immersion time of each film prepared bya non-hydrophilic resin composition of Comparative Examples 1b to 2b.

DESCRIPTION OF EMBODIMENTS

Next, each of the first present invention to the fourth presentinvention will be described in more detail giving preferableembodiments.

The first present invention and the second present invention relate to amethod for removing radioactive cesium, and the main characteristic isto use a hydrophilic resin composition capable of immobilizingradioactive cesium, the hydrophilic resin composition comprising a metalferrocyanide compound a representative example of which is Prussian bluedispersed in a hydrophilic resin having a particular structure.

Moreover, the third present invention and the fourth present inventionrelate to a method for removing radioactive iodine and radioactivecesium, and the main characteristic is to use a hydrophilic resincomposition capable of immobilizing both of radioactive iodine andradioactive cesium, the hydrophilic resin composition comprising a metalferrocyanide compound a representative example of which is Prussian bluedispersed in a hydrophilic resin having a particular structure.

Here, the “hydrophilic resin” in the present invention means a resinthat has a hydrophilic group in the molecule thereof but is insoluble towater, hot water, and so on, and the hydrophilic resin in the presentinvention is clearly distinguished from a water soluble resin such aspolyvinyl alcohols, polyvinyl pyrrolidones, polyacrylic acids, andcellulose derivatives.

Each of the hydrophilic resin compositions that characterize the firstpresent invention to the fourth present invention comprises ahydrophilic resin having a particular structure and a metal ferrocyanidecompound a representative example of which is Prussian blue, andradioactive cesium can favorably be removed from radioactive wasteliquid or a radioactive solid matter in the case where any of thehydrophilic resin compositions is used. The present inventors consideras follows with regard to the reason why it becomes possible to removeradioactive cesium by using these hydrophilic resin compositions. Firstof all, any of the hydrophilic resins used in the first presentinvention to the fourth present invention has a hydrophilic segment inthe structure thereof and therefore exhibits excellent water absorbencydue to the presence of the hydrophilic segment. For this reason, it isconsidered that ionized radioactive cesium that is an object ofprocessing is quickly taken in the resin. And in any of the removingmethods of the first present invention to the fourth present invention,the hydrophilic resin composition comprising a metal ferrocyanidecompound a representative example of which is Prussian blue dispersed ina hydrophilic resin that exhibits such a water-absorbing function isused, and, as described later, it is known that selective adsorption orthe like by a cesium ion occurs on the metal ferrocyanide compound arepresentative example of which is Prussian blue and the metalferrocyanide compound can be utilized for the removal of the cesium ion.It is considered that since the above-described hydrophilic resincapable of quickly taking in ionized radioactive cesium that is anobject of processing and the metal ferrocyanide compound arepresentative example of which is Prussian blue are present together inany of the hydrophilic resin compositions that characterize the firstpresent invention to the fourth present invention, radioactive cesium isfixed to the dispersed metal ferrocyanide compound more quickly and moreeffectively and immobilized by the resin, and, as a result thereof, theeffective removal of radioactive cesium can be achieved by the firstpresent invention to the fourth present invention. In addition,according to the third present invention and the fourth presentinvention in which the resins the structures of which are different fromthe structures of the resins used in the first present invention and thesecond present invention are used, it becomes possible to apply removingprocessing to not only radioactive cesium as described above, but alsoboth of radioactive iodine and radioactive cesium, however the reasonfor this will be described later.

[Metal Ferrocyanide Compound]

Here, the metal ferrocyanide compound used in each of the first presentinvention to the fourth present invention is a compound represented bythe following general formula (1). Among the metal ferrocyanidecompounds, metal ferrocyanide compounds called Prussian blue that havebeen widely used as a colorant are included, however any of the metalferrocyanide compounds can preferably be used in the present invention.

A_(x)M_(y)[Fe(CN)₆]  (1)

[In the formula, A is any one selected from K, Na, and NH₄, M is any oneselected from Ca, Mn, Fe, Co, Ni, Cu, and Zn, x and y satisfy anequation x+ny=4 (x is an integer from 0 to 3), and n represents avalence number of M]

More specific examples of the metal ferrocyanide compounds include thecompounds represented by the following general formula (A) and (B) andcalled Prussian blue, these compounds are pigments that has long beenproduced, and the color names thereof has a lot of trivial names such asPrussian blue, Milori blue, and Berlin blue.

MFe[Fe(CN)₆] (A) [in the formula, M=NH₄, K or Fe]

MK₂[Fe(CN)₆] (B) [in the formula, M=Ni or Co]

It has already been publicly known that the above-described Prussianblue can be used for removing radioactive cesium, and in fact Prussianblue has been used at the time of accident in Chernobyl nuclear powerplant. The mechanism of removing radioactive cesium by Prussian blue hasnot been fully elucidated, however two views, “ion exchange” and“adsorption”, have been proposed.

The view of “ion exchange” is that when a cesium ion contacts withammonium Prussian blue that is a kind of Prussian blue, a cation in thePrussian blue replaces the cesium ion by ion exchange, the radioactivecesium is immobilized, and the cesium ion can be removed. On the otherhand, the “adsorption” is a view that the cesium ion is selectivelyadsorbed in pores having an interval of 0.5 nm that the crystal ofPrussian blue has and, as a result thereof, the cesium ion can beremoved. At the moment, it has not been clear which view is right,however the effect of removing cesium by Prussian blue has been provedin any event. In the first present invention to the fourth presentinvention, it becomes possible to provide a method capable of applyingremoving processing to radioactive cesium more efficiently, simply, andeconomically by using the hydrophilic resin composition comprising theaforementioned hydrophilic resin having a hydrophilic segment and ametal ferrocyanide compound a representative example of which is thePrussian blue dispersed therein. Hereinafter, the description will bemade with regard to the hydrophilic resin each constituting the firstpresent invention to the fourth present invention.

[Hydrophilic Resin] (First Hydrophilic Resin)

The hydrophilic resin that characterizes the first present invention(hereinafter, referred to as the first hydrophilic resin) has acharacteristic of having a hydrophilic segment comprising a hydrophiliccomponent as a constituent unit. Namely, the first hydrophilic resin maybe a hydrophilic resin having, in the structure thereof, a hydrophilicsegment comprising a hydrophilic component as a constituent unit.Specifically, the hydrophilic resin comprises at least one selected fromthe group consisting of hydrophilic resins such as a hydrophilicpolyurethane resin, a hydrophilic polyurea resin, and a hydrophilicpolyurethane-polyurea resin each having a hydrophilic segment. Eachhydrophilic segment in these hydrophilic resins is randomly bondedthrough a urethane bond, a urea bond, a urethane-urea bond, or the likein the case where a chain extender is not used at the time ofsynthesizing the hydrophilic resin. Moreover, in the case where thechain extender is used at the time of synthesizing the hydrophilicresin, the structure is made so that a short chain that is a residue ofthe chain extender is present, together with the above-described bonds,between the above-described bonds.

Furthermore, the first hydrophilic resin composition that can beutilized for the method for removing radioactive cesium in the firstpresent invention (hereinafter, referred to as the first hydrophilicresin composition) has a characteristic of comprising the firsthydrophilic resin. The hydrophilic resin has a characteristic of havinga hydrophilic segment comprising a hydrophilic component as aconstituent unit and, as described previously, exhibits insolubility towater and hot water. Specific examples include a hydrophilicpolyurethane resin, a hydrophilic polyurea resin, and a hydrophilicpolyurethane-polyurea resin each having a hydrophilic segment, and atleast one selected from the group consisting of a hydrophilicpolyurethane resin, a hydrophilic polyurea resin, and a hydrophilicpolyurethane-polyurea resin having a hydrophilic segment can be used.

The first hydrophilic resin having a hydrophilic segment as describedabove is obtained by reacting, for example, an organic polyisocyanatewith a compound having a high molecular weight hydrophilic polyol and/orpolyamine being a hydrophilic component. Hereinafter, compounds used forsynthesizing the first hydrophilic resin will be described.

As a hydrophilic component used for synthesizing the first hydrophilicresin, for example, a high molecular weight hydrophilic polyol and/or apolyamine having, at a terminal thereof, a hydrophilic group such as ahydroxyl group, an amino group, and a carboxyl group and having a weightaverage molecular weight (a value in terms of standard polystyrenemeasured by GPC) in a range of 400 to 8,000 are preferable. Morespecifically, the hydrophilic component is, for example, a hydrophilicpolyol having a hydroxyl group at a terminal thereof, and examplesthereof include polyethylene glycol, polyethyleneglycol/polytetramethylene glycol copolyols, polyethyleneglycol/polypropylene glycol copolyols, polyethylene glycol adipatepolyol, polyethylene glycol succinate polyol, polyethylene glycol/polyε-lactone copolyols, polyethylene glycol/polyvalero lactone copolyols.

Moreover, the hydrophilic component used for synthesizing the firsthydrophilic resin is a hydrophilic polyamine having an amino group at aterminal thereof, and examples thereof include polyethylene oxidediamine, polyethylene oxide-propylene oxide diamine, polyethylene oxidetriamine, and polyethylene oxide-polypropylene oxide triamine. Otherhydrophilic components include ethylene oxide adducts having a carboxylgroup or a vinyl group.

Another Polyol, polyamine, polycarboxylic acid, or the like not having ahydrophilic chain can also be used together with the above-describedhydrophilic component for the purpose of imparting water resistance tothe first hydrophilic resin.

The organic polyisocyanate used in the synthesis of the firsthydrophilic resin is not particularly limited, and any of publicly knownorganic polyisocyanates used in the conventional synthesis ofpolyurethane resins can be used. As a preferable organic polyisocyanate,for example, 4,4′-diphenylmethanediisocyanate (hereinafter, abbreviatedas MDI), dicyclohexylmethane-4,4′-diisocyanate (hereinafter, abbreviatedas hydrogenated MDI), isophorone diisocyanate, 1,3-xylylenediisocyanate, 1,4-xylylene diisocyanate, 2,4-tolylene diisocyanate,m-phenylene diisocyanate, p-phenylene diisocyanate, and so on can beused, or a polyurethane prepolymer or the like obtained by reacting theabove organic polyisocyanate with a low molecular weight polyol orpolyamine so as to form a terminal isocyanate can also be used.

Moreover, as a chain extender used in synthesizing the first hydrophilicresin as necessary, any of the publicly known chain extenders such as,for example, a low molecular weight diol and diamine can be used withoutparticular limitation. Specific examples of the chain extender includeethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol,ethylenediamine, and hexamethylenediamine.

It is preferable that the first hydrophilic resin having a hydrophilicsegment in the molecular chain, the first hydrophilic resin obtained byallowing the above described raw material components to react, has aweight average molecular weight (a value in terms of standardpolystyrene measured by GPC, the same applies hereinafter) in a range of3,000 to 800,000. More preferable weight average molecular weight is ina range of 5,000 to 500,000.

It is preferable that the content of the hydrophilic segment in theparticularly suitable first hydrophilic resin that can be utilized forthe method for removing radioactive cesium of the first presentinvention is in a range of 20 to 80 mass %, more preferably in a rangeof 30 to 70 mass %. It is not preferable that a resin having ahydrophilic segment content of less than 20 mass % is used because thehydrophilic resin tends to be inferior in water-absorbing performanceand the removing property of radioactive cesium tends to bedeteriorated. On the other hand, it is not preferable that the resinhaving a hydrophilic segment content exceeding 80 mass % is used becausethe hydrophilic resin becomes inferior in water resistance.

(Second Hydrophilic Resin)

The second hydrophilic resin that characterizes the second presentinvention (hereinafter, referred to as the second hydrophilic resin)comprises at least one selected from the group consisting of ahydrophilic polyurethane resin, a hydrophilic polyurea resin, and ahydrophilic polyurethane-polyurea resin having a hydrophilic segmentcomprising a hydrophilic component as a constituent unit and furtherhaving, in the main chain and/or a side chain in the structure thereof,a polysiloxane segment. Each of these segments is randomly bondedthrough a urethane bond, a urea bond, a urethane-urea bond, or the likein the case where a chain extender is not used at the time ofsynthesizing the second hydrophilic resin. In the case where the chainextender is used at the time of synthesizing the second hydrophilicresin, the structure is made so that a short chain that is a residue ofthe chain extender is present, together with the above-described bonds,between the above-described bonds.

The second hydrophilic resin has a hydrophilic segment in the structurethereof in the same way as in the case of the previously described firsthydrophilic resin and, in addition to this, is also required to have apolysiloxane segment in the structure thereof. By constituting thesecond hydrophilic resin as described here, more useful effect can beobtained and it becomes possible to achieve the above-described intendedpurpose of the second present invention. Here, the polysiloxane segmentintroduced in the resin molecule is fundamentally hydrophobic(water-repellent), however in the case where the polysiloxane segment isintroduced in the resin structure by an amount of a particular range,the resin is known to become a resin having “environmentalresponsiveness” (KOBUNSHI RONBUNSHU vol. 48, no. 4, p. 227 (1991)).“Environmental responsiveness” in a resin as described in the literatureis a phenomenon that the surface of the resin is completely covered by apolysiloxane segment in a dry state, however, in the state in which theresin is immersed in water, the polysiloxane segment is buried in theresin.

In the second present invention, the phenomenon of the “environmentalresponsiveness” exhibited by the resin by introducing a polysiloxanesegment in the structure of the resin to be used is utilized for theremoving processing of radioactive cesium, and thereby the processing ismade more effective. The second hydrophilic resin used in the presentinvention exhibits excellent water absorbency due to the hydrophilicsegment present in the structure thereof in the same way as in the caseof the aforementioned first hydrophilic resin, can quickly take inionized radioactive cesium, and is effective for the removing processingof the ionized radioactive cesium. However, according to the studies ofthe present inventors, there has been a problem as described below inputting a hydrophilic resin into practical use in the case where thestructural characteristic of the resin to be used is only to have ahydrophilic segment in the structure thereof. Namely, it becomesnecessary in applying the removing processing to radioactive cesium to,for example, make a resin composition to be used in a form such as asheet form by applying a base material with the resin composition and afilm form and to immerse the sheet or the film in the waste liquidcontaining radioactive cesium, or to make the sheet or the film as acover for the solid matter containing radioactive cesium. In such cases,durability to the above-described removing processing of radioactivecesium is required for the resin film or the like to be used. However,in the case where the resin having such a structure as theaforementioned first hydrophilic resin has, it is hard to say that thedurability is sufficient depending on the use state. The presentinventors have made diligent studies against the problem and, as aresult thereof, have found that the water resistance and the blockingresistance performance (sticking resistance) of the surface can beimproved by further introducing a polysiloxane segment in the molecule(in the structure) of the hydrophilic resin to be used. Namely, theresin constitution by which the resin film or the like exhibits asufficient water resistant function and the like and more effectiveremoving processing of radioactive cesium can be applied is achievedeven in the case of the above-described use form by making the structureof resin so as to be a structure such as the second hydrophilic resin.

It is considered that, in the second present invention, the secondhydrophilic resin composition in which the metal ferrocyanide compound arepresentative example of which is Prussian blue is dispersed togetherwith the second hydrophilic resin exhibiting the above-describedexcellent function is used for the removing processing of radioactivecesium and therefore the radioactive cesium has been fixed andimmobilized more quickly and effectively by the dispersed Prussian blueor the like from the aforementioned reason.

Next, the description will be made with regard to a raw material forforming the second hydrophilic resin that can realize theabove-described excellent performance. A preferable second hydrophilicresin is a hydrophilic resin having a hydrophilic segment in thestructure thereof, having, in the main chain or a side chain in thestructure thereof, a polysiloxane segment, and obtained by reacting anorganic polyisocyanate, a high molecular weight hydrophilic polyoland/or polyamine being a hydrophilic component, and a compound having atleast one active hydrogen-containing group and a polysiloxane segment inthe same molecule. Specifically, the preferable second hydrophilic resinis a hydrophilic resin comprising at least one selected from the groupconsisting of a hydrophilic polyurethane resin, hydrophilic polyurearesin, and a hydrophilic polyurethane-polyurea resin. As described here,the second hydrophilic resin is obtained from, as a part of a rawmaterial, the compound having at least one active hydrogen-containinggroup and a polysiloxane segment in the same molecule, and examples of aspecific polysiloxane compound used in synthesizing the secondhydrophilic resin, the specific polysiloxane compound usable forintroducing a polysiloxane segment in the second hydrophilic resinmolecule include polysiloxane compounds having one or two or morereactive groups such as an amino group, an epoxy group, a hydroxylgroup, a mercapto group, and a carboxyl group in the molecule.Preferable examples of the polysiloxane compound having theabove-described reactive groups include the following compounds.

Amino-Modified Polysiloxane Compounds

Epoxy-Modified Polysiloxane Compounds

Alcohol-Modified Polysiloxane Compounds

Mercapto-Modified Polysiloxane Compounds

Carboxyl-Modified Polysiloxane Compounds

Among the polysiloxane compounds having an active hydrogen-containinggroup as described above, polysiloxane polyols and polysiloxanepolyamines are particularly useful. In addition, any of the listedcompounds is a preferable compound used in the second present invention,however the present invention is not limited to these exemplifiedcompounds. Accordingly, not only above-described exemplified compoundsbut also any of the compounds currently sold and readily available fromthe market can be used in the second present invention.

As described previously, it is preferable to use a high molecular weighthydrophilic polyol and/or polyamine being a hydrophilic component forsynthesizing the second hydrophilic resin having a hydrophilic segment.A hydrophilic compound having a hydroxyl group, an amino group, acarboxyl group, or the like and having a weight average molecular weightin a range of 400 to 8,000 is preferable as such a hydrophiliccomponent. The preferable specific examples of the hydrophilic componentare the same as the preferable specific examples described previously inthe first hydrophilic resin, and the description is omitted. Moreover,the organic polyisocyanates and chain extenders described in thedescription of the first hydrophilic resin can also be used in additionto the hydrophilic component in synthesizing the second hydrophilicresin.

Another polyol, polyamine, polycarboxylic acid, and so on not having ahydrophilic chain can be used together with the above-describedhydrophilic component in the same way as in the case of the firsthydrophilic resin for the purpose of imparting water resistance to thesecond hydrophilic resin.

It is preferable that the second hydrophilic resin having a hydrophilicsegment and a polysiloxane segment in the molecular chain, the secondhydrophilic resin obtained using the above-described raw materialcomponents, has a weight average molecular weight (in terms of standardpolystyrene measured by GPC) in a range of 3,000 to 800,000. Morepreferable weight average molecular weight is in a range of 5,000 to500,000.

It is preferable that the content of the polysiloxane segment in thesecond hydrophilic resin particularly suitable for using in the secondpresent invention is in a range of 0.1 to 12 mass %, particularlypreferably in a range of 0.5 to 10 mass %. It is not preferable that thecontent of the polysiloxane segment is less than 0.1 mass % because theexhibition of the water resistance and the blocking resistance of thesurface that is the intended purpose of the present invention becomesinsufficient, and, on the other hand, it is not preferable that thecontent of the polysiloxane segment exceeds 12 mass % because the waterrepellency due to the polysiloxane segment becomes strong resulting indeterioration of the water-absorbing performance.

Moreover, it is preferable that the content of the hydrophilic segmentin the second hydrophilic resin particularly suitable for using in thesecond present invention is in a range of 20 to 80 mass %, further morepreferably in a range of 30 to 70 mass %. When the content of thehydrophilic segment is less than 20 mass %, the water-absorbingperformance is deteriorated. On the other hand, it is not preferablethat the content of the hydrophilic segment exceeds 80 mass % becausethe second hydrophilic resin becomes inferior in water resistance.

Hereinafter, the description will be made with regard to eachhydrophilic resin used in the third or the fourth present invention,however in the third or the fourth present invention, there is adifference when compared with the above-described first or secondpresent invention in that not only radioactive cesium present in aradioactive waste liquid and/or a radioactive solid matter but also bothof radioactive iodine and radioactive cesium can be removed.

(Third Hydrophilic Resin)

The hydrophilic resin that characterizes the third present invention(hereinafter, referred to as the third hydrophilic resin) has acharacteristic of having: a hydrophilic segment comprising a hydrophiliccomponent as a constituent unit; and at least one tertiary amino group.The third hydrophilic resin may be a hydrophilic resin having: ahydrophilic segment comprising a hydrophilic component as a constituentunit; and at least one tertiary amino group; in the structure thereof.Each of these segments is randomly bonded through a urethane bond, aurea bond, a urethane-urea bond, or the like in the case where a chainextender is not used at the time of synthesizing the third hydrophilicresin. In the case where a chain extender is used at the time ofsynthesizing the third hydrophilic resin, the structure is made so thata short chain that is a residue of the chain extender is present,together with the above-described bonds, between the above-describedbonds.

The third hydrophilic resin composition that can be utilized for themethod for removing radioactive iodine and radioactive cesium in thethird present invention (hereinafter, referred to as the thirdhydrophilic resin composition) comprises the third hydrophilic resin anda metal ferrocyanide compound a representative example of which isPrussian blue, and it becomes possible to apply removing processing toboth of radioactive iodine and radioactive cesium together by using thecomposition. The present inventors consider as follows with regard tothe reason why such processing becomes possible. First of all, the thirdhydrophilic resin exhibits excellent water absorbency due to thehydrophilic segment in the structure thereof, and with regard toexhibiting excellent water absorbency, the third hydrophilic resin issimilar to the hydrophilic resins that constitute the first or thesecond present invention the object of which is to remove radioactivecesium, and thereby the effect on the removal of radioactive cesiumsimilar to the effect of the hydrophilic resins that constitute thefirst or the second present invention can be obtained.

In the third hydrophilic resin, a tertiary amino group is furtherintroduced in the main chain and/or a side chain in the structurethereof, thereby an ion bond is formed between ionized radioactiveiodine and the tertiary amino group, and as a result thereof radioactiveiodine is considered to be fixed in the third hydrophilic resin inaddition to the effect on the above-described removal of radioactivecesium. However, since the above-described ion bond easily dissociatesunder the presence of moisture, the radioactive iodine is considered tobe discharged again from the resin after a certain period of time ispassed, and the present inventors have anticipated that it is difficultto remove radioactive iodine in a state in which the fixing state ofradioactive iodine within the resin is immobilized. However, as a resultof studies by the present inventors, it has been found that theconically bonded radioactive iodine, in fact, remains to be fixed withinthe resin after a long period of time is passed. The reason isuncertain, however the present inventors consider as follows. Namely,the present inventors estimate that, in the third hydrophilic resin usedin the present invention, a hydrophobic part is also present in themolecule and the hydrophobic part surrounds, after the ion bond isformed between the tertiary amino group in the resin and radioactiveiodine, the circumferences of the hydrophilic part (the hydrophilicsegment) and the ion bond. It is considered from the reason as describedhere that radioactive iodine can be immobilized within the resin and theremoval of radioactive iodine becomes possible by using the thirdhydrophilic resin composition comprising the third hydrophilic resinhaving a particular structure in the present invention.

Furthermore, as described in detail previously in the description of thefirst present invention and the second present invention, the removingprocessing of radioactive cesium in addition to the above-describedremoval of radioactive iodine is also made possible by using the thirdhydrophilic resin composition comprising a hydrophilic resin having ahydrophilic segment and a metal ferrocyanide compound a representativeexample of which is Prussian blue, and thereby applying removingprocessing to both of radioactive iodine and radioactive cesium togetherhas been achieved.

The third hydrophilic resin comprises the third hydrophilic resin, andthe hydrophilic resin has a characteristic of having: a hydrophilicsegment comprising a hydrophilic component as a constituent unit; and atleast one tertiary amino group. Specific examples of the hydrophilicresin include at least one selected from the group consisting of ahydrophilic polyurethane resin, a hydrophilic polyurea resin, and ahydrophilic polyurethane-polyurea resin each having a hydrophilicsegment and having, in the main chain and/or a side chain in thestructure thereof, a tertiary amino group.

Such a hydrophilic resin is obtained by reacting an organicpolyisocyanate, a high molecular weight hydrophilic polyol and/orpolyamine being a hydrophilic component, and a compound having at leastone active hydrogen-containing group and at least one tertiary aminogroup in the same molecule. Namely, examples of a compound used forintroducing a hydrophilic segment and a tertiary amino group in thestructure of the third hydrophilic resin include a compound having atleast one active hydrogen-containing group (reactive group) in themolecule and having, in the molecular chain, a tertiary amino group.Examples of the compound having at least one active hydrogen-containinggroup include a compound having a reactive group such as an amino group,an epoxy group, a hydroxyl group, a mercapto group, an acid halidegroup, a carboxyester group, and an acid anhydride group.

Preferable examples of the above-described tertiary aminogroup-containing compound having a reactive group include compoundsrepresented by the following formulas (2) to (4).

[In the formula (2), R₁ represents an alkyl group having 20 or lesscarbon atoms, an alicyclic group, or an aromatic group (which may besubstituted with a halogen or an alkyl group), R₂ and R₃ respectivelyrepresent an lower alkylene group which may be linked through —O—, —CO—,—COO—, —NHCO—, —S—, —SO—, —SO₂—, or the like, X and Y represent areactive group such as —OH, —COOH, —NH₂, —NHR₁ (the definition of R₁ isthe same definition as described above), or —SH, and X and Y may be thesame or different; moreover, X and Y may be an epoxy group, an alkoxygroup, an acid halide group, an acid anhydride group, or a carboxyestergroup capable of deriving the above reactive group.]

[In the formula (3), the definition of R₁, R₂, R₃, X, and Y is the samedefinition as in the above formula (2), however the two R₁ may form acyclic structure; R₄ represents —(CH₂)_(n)— (n is an integer of 0 to20).]

X—W—Y  (4)

[In the formula (4), the definition of X and Y is the same definition asin the above formula (2), W represents a nitrogen-containingheterocyclic ring, a nitrogen- and oxygen-containing heterocyclic ring,or a nitrogen- and sulfur-containing heterocyclic ring.]

Specific examples of the compounds represented by the above generalformula (2), (3), and (4) include the following compounds. The compoundsinclude

N,N-dihydroxyethyl-methylamine, N,N-dihydroxyethyl-ethylamine,N,N-dihydroxyethyl-isopropylamine, N,N-dihydroxyethyl-n-butylamine,N,N-dihydroxyethyl-t-butylamine, methyliminobispropylamine,N,N-dihydroxyethylaniline, N,N-dihydroxyethyl-m-toluidine,N,N-dihydroxyethyl-p-toluidine, N,N-dihydroxyethyl-m-chloroaniline,N,N-dihydroxyethylbenzylamine,N,N-dimethyl-N′,N′-dihydroxyethyl-1,3-diaminopropane,N,N-diethyl-N′,N′-dihydroxyethyl-1,3-diaminopropane,N-hydroxyethyl-piperazine, N,N-dihydroxyethyl-piperazine,N-hydroxyethoxyethyl-piperazine, 1,4-bisaminopropyl-piperazine,N-aminopropyl-piperazine, dipicolinic acid, 2,3-diaminopyridine,2,5-diaminopyridine, 2,6-diamino-4-methylpyridine,2,6-dihydroxypyridine, 2,6-pyridine-dimethanol,2-(4-pyridyl)-4,6-dihydroxypyrimidine, 2,6-diaminotriazine,2,5-diaminotriazole, and 2,5-diaminooxazole.

Moreover, an ethylene oxide adduct or a propylene oxide adduct of theabove tertiary amino compounds may also be used in the presentinvention. Examples of the adduct include compounds represented by thefollowing structural formula. In addition, m in the following formularepresents an integer of 1 to 60, and n represents an integer of 1 to 6.

As the organic polyisocyanate used for synthesizing the thirdhydrophilic resin, the organic polyisocyanates described previously inthe description of the first hydrophilic resin can be used.

Moreover, as the hydrophilic component used together with theabove-described organic polyisocyanate for synthesizing the hydrophilicresin that characterizes the present invention, a hydrophilic compoundhaving a hydroxyl group, an amino group, a carboxyl group, or the likeand having a weight average molecular weight in a range of 400 to 8,000is preferable. The preferable specific examples of the hydrophiliccomponent are the same as the preferable specific examples describedpreviously in the description of the first hydrophilic resin, and thedescription is omitted.

Another polyol, polyamine, polycarboxylic acid, or the like not having ahydrophilic component can be used together with the above-describedhydrophilic component in the same way as in the case of the firsthydrophilic resin for the purpose of imparting water resistance to thethird hydrophilic resin. Moreover, as the chain extender used insynthesizing the third hydrophilic resin as necessary, the chainextenders described previously in the description of the firsthydrophilic resin can be used.

It is preferable that the third hydrophilic resin obtained using theabove-described raw material components, the third hydrophilic resinhaving a hydrophilic segment and having, in the molecular chain, atertiary amino group, has a weight average molecular weight (in terms ofpolystyrene measured by GPC) in a range of 3,000 to 800,000. Furthermore preferable weight average molecular weight is in a range of 5,000to 500,000.

As the particularly suitable third hydrophilic resin used for the methodfor removing radioactive iodine and radioactive cesium of the thirdpresent invention, it is preferable that the content of the tertiaryamino group in the resin is 0.1 to 50 eq (equivalent)/kg, morepreferably 0.5 to 20 eq/kg. It is not preferable that the content of thetertiary amino group is less than 0.1 eq/kg, namely less than 1 aminogroups per 10,000 molecular weight, because the exhibition of theradioactive iodine removing property that is the intended purpose of thepresent invention becomes insufficient, and, on the other hand, it isnot preferable that the content of the tertiary amino group 50 eq/kg ormore, namely 500 amino groups or more per 10,000 molecular weight,because the hydrophobicity becomes strong due to reduction of thehydrophilic part in the resin and the third hydrophilic resin becomesinferior in water-absorbing performance.

Moreover, it is preferable that the content of the hydrophilic segmentin the particularly suitable third hydrophilic segment in the case wherethe third hydrophilic resin is used in the third present invention is ina range of 20 to 80 mass %, further more preferably in an range of 30 to70 mass %. It is not preferable that the content of the hydrophilicsegment is less than 20 mass % because the third hydrophilic resinbecomes inferior in water-absorbing performance and the removingproperty of radioactive iodine becomes deteriorated. On the other hand,it is not preferable that the content of the hydrophilic segment exceeds80 mass % because the third hydrophilic resin becomes inferior in waterresistance.

Hereinafter, the description will be made with regard to the hydrophilicresin used in the fourth present invention. Also in the fourth presentinvention, both of radioactive iodine and radioactive cesium present ina radioactive waste liquid and/or a radioactive solid matter can beremoved together by using a hydrophilic resin having a particularstructure together with a metal ferrocyanide compound a representativeexample of which is Prussian blue in the same way as in theabove-described third present invention. Furthermore, the hydrophilicresin used in the fourth present invention exhibits a sufficient waterresistant function in the same way as in the case of the secondhydrophilic resin described previously, and the practicability becomesfurther improved compared with the practicability of the third presentinvention by using the hydrophilic resin used in the fourth presentinvention.

(Fourth Hydrophilic Resin)

The hydrophilic resin that characterizes the fourth present invention(hereinafter, referred to as the fourth hydrophilic resin) has acharacteristic of having a hydrophilic segment comprising a hydrophiliccomponent as a constituent unit and having, in the main chain and/or aside chain in the structure, at least one tertiary amino group and apolysiloxane segment. Namely, the fourth hydrophilic resin may be ahydrophilic resin having: a hydrophilic segment comprising a hydrophiliccomponent as a constituent unit; at least one tertiary amino group; anda polysiloxane segment; in the structure thereof. Each of these segmentsis randomly bonded through a urethane bond, a urea bond, a urethane-ureabond, or the like in the case where a chain extender is not used at thetime of synthesizing the fourth hydrophilic resin. Moreover, in the casewhere a chain extender is used at the time of synthesizing the fourthhydrophilic resin, the structure is made so that a short chain that is aresidue of the chain extender is present, together with theabove-described bonds, between the above-described bonds.

The fourth hydrophilic resin composition that can be utilized for themethod for removing radioactive iodine and radioactive cesium in thefourth present invention (hereinafter, referred to as the fourthhydrophilic resin composition) comprises the fourth hydrophilic resinhaving a hydrophilic segment and a tertiary amino group in the structurethereof and a metal ferrocyanide compound a representative example ofwhich is Prussian blue in the same way as in the case of the thirdhydrophilic resin. Therefore, it becomes possible to apply removingprocessing to both of radioactive iodine and radioactive cesium togetherby using the fourth hydrophilic resin composition in the same way as inthe case of using the third hydrophilic resin composition comprising thethird hydrophilic composition. The detailed reason is similar to thereason described previously in the case of the third hydrophilic resincomposition, and therefore the description is omitted.

The fourth hydrophilic resin is required to be a hydrophilic resinhaving a polysiloxane segment in the structure thereof in addition tothe above-described requirement. Here, as described in the descriptionof the second hydrophilic resin, the polysiloxane segment introduced inthe resin molecule is fundamentally hydrophobic (water-repellent),however in the case where the polysiloxane segment is introduced in theresin structure by an amount of a particular range, the resin is knownto become a resin having “environmental responsiveness” (KOBUNSHIRONBUNSHU vol. 48, no. 4, p. 227 (1991)).

The fourth present invention utilizes the phenomenon of the“environmental responsiveness” exhibited by the resin by introducing apolysiloxane segment for the removing processing of radioactive iodine.As described previously, when an ion bond is formed between the tertiaryamino group introduced in the hydrophilic resin used in the presentinvention and radioactive iodine that is an object of processing, thehydrophilicity of the resin is further increased, and thereby converselythere is a risk that a problem as described below occurs. Namely, sincethe removing processing is applied immobilizing radioactive iodine andradioactive cesium as described later in the method for removingradioactive iodine and radioactive cesium of the fourth presentinvention, it is preferable that the fourth hydrophilic resin is used asa form of, for example, a film form or the like, however, in the case,when the amount of the radioactive iodine to be processed is too large,there is a risk that the radioactive iodine poses an obstacle for thewater resistance required for the resin. Against this risk, the resinconstitution by which the resin to be used exhibits a sufficient waterresistant function and more effective removing processing of radioactiveiodine can be applied is realized even in the above-described case byfurther introducing a polysiloxane segment in the molecule (in thestructure) of the hydrophilic resin to be used in the fourth presentinvention. Namely, the fourth hydrophilic resin becomes more useful whenused in the removing processing of radioactive iodine as a result ofrealizing the water resistance of the resin and the blocking resistanceperformance (sticking resistance) of the surface by introducing apolysiloxane segment in addition to the water-absorbing performance dueto the hydrophilic segment introduced in the structure thereof and thefixing performance to radioactive iodine due to the tertiary aminogroup.

Furthermore, in the fourth present invention, as described in the firstpresent invention to the third present invention, the removingprocessing of radioactive cesium in addition to the above-describedremoval of radioactive iodine is also made possible by using the fourthhydrophilic resin composition comprising a metal ferrocyanide compound arepresentative example of which is Prussian blue, and thereby theprocessing of radioactive iodine and radioactive cesium together hasbeen achieved.

Next, the description will be made with regard to a raw material forforming the fourth hydrophilic resin that realizes the above-describedperformance. The fourth hydrophilic resin has a characteristic of havinga hydrophilic segment, a tertiary amino group, and a polysiloxanesegment in the structure thereof. Therefore, it is preferable to use, asa part of a raw material, a polyol having at least one tertiary aminogroup or a polyamine having at least one tertiary amino group and acompound having at least one active hydrogen-containing group and apolysiloxane segment in the same molecule for the purpose of obtainingthe hydrophilic resin. It is preferable to use a tertiary aminogroup-containing compound as listed below as a compound for introducingthe tertiary amino group in the fourth hydrophilic resin. Namely, acompound having at least one active hydrogen-containing group(hereinafter, sometimes described as a reactive group) such as, forexample, an amino group, an epoxy group, a hydroxyl group, a mercaptogroup, an acid halide group, a carboxyester group, and an acid anhydridegroup in the molecule and having, in the molecular chain, a tertiaryamino group is used. Specific preferable examples of the tertiary aminogroup-containing compound having a reactive group as described above arethe same as the specific preferable examples described in thedescription of the third hydrophilic resin, and therefore thedescription is omitted.

Moreover, the fourth hydrophilic resin has a characteristic of having apolysiloxane segment in the structure thereof. Examples of thepolysiloxane compound usable for introducing a polysiloxane segment inthe fourth hydrophilic resin molecule include a compound having one ortwo or more of reactive groups such as, for example, an amino group, anepoxy group, a hydroxyl group, a mercapto group, and a carboxyl group inthe molecule. Preferable examples of the polysiloxane compound havingthe reactive groups as described above are the same as the preferableexamples described in the description of the second hydrophilic resin,and therefore the description is omitted.

It is preferable that the fourth hydrophilic resin obtained using theabove-described raw material components, the fourth hydrophilic resinhaving a hydrophilic segment and having, in the molecular chain, atertiary amino group and a polysiloxane segment, has a weight averagemolecular weight (in terms of standard polystyrene measured by GPC) in arange of 3,000 to 800,000. More preferable weight average molecularweight is in a range of 5,000 to 500,000.

It is preferable that the content of the tertiary amino group in theparticularly suitable fourth hydrophilic resin used for the method forremoving radioactive iodine and radioactive cesium of the fourth presentinvention is in a range of 0.1 to 50 eq (equivalent)/kg, further morepreferably 0.5 to 20 eq/kg. It is not preferable that the content of thetertiary amino group is less than 0.1 eq/kg, namely less than 1 aminogroups per 10,000 molecular weight, because the exhibition of theradioactive iodine removing property that is the intended purpose of thefourth present invention, becomes insufficient, and, on the other hand,it is not preferable that the content of the tertiary amino groupexceeds 50 eq/kg, namely exceeding 500 amino groups per 10,000 molecularweight, because the hydrophobicity becomes strong due to reduction ofthe hydrophilic part in the resin and the fourth hydrophilic resinbecomes inferior in water-absorbing performance.

Moreover, the content of the polysiloxane segment in the resin as theparticularly suitable fourth hydrophilic resin used for the method forremoving radioactive iodine and radioactive cesium of the fourth presentinvention is in a range of 0.1 to 12 mass %, particularly preferably 0.5to 10 mass %. It is not preferable that the content of the polysiloxanesegment is less than 0.1 mass % because the exhibition of the waterresistance and the blocking resistance of the surface that is theintended purpose of the present invention becomes insufficient, and, onthe other hand, it is not preferable that the content of thepolysiloxane segment exceeds 12 mass % because water repellency due tothe polysiloxane segment becomes strong, the water-absorbing performanceis deteriorated, and the radioactive iodine removing property isinhibited.

Moreover, it is preferable that the content of the hydrophilic segmentin the particularly suitable fourth hydrophilic resin in the case wherethe fourth hydrophilic resin is used in the fourth present invention isin a range of 20 to 80 mass %, further more preferably in a range of 30to 70 mass %. When the content of the hydrophilic segment is less than20 mass %, the water-absorbing performance of the fourth hydrophilicresin is deteriorated and the radioactive iodine removing propertybecomes insufficient. On the other hand, it is not preferable that thecontent of the hydrophilic segment exceeds 80 mass % because the fourthhydrophilic resin becomes inferior in water resistance.

(Method for Producing Hydrophilic Resin Composition)

The hydrophilic resin composition that is suitable for the method forremoving radioactive cesium in the first or the second present inventionand the method for removing radioactive iodine and radioactive cesium inthe third or the fourth present invention is obtained by dispersing ametal ferrocyanide compound a representative example of which isPrussian blue (hereinafter, the description will be made taking Prussianblue as an example) in any one of the above-described hydrophilic resinsof the first present invention to the fourth present invention.Specifically, the hydrophilic resin composition can be produced byputting Prussian blue and a dispersion solvent into any one of the firstto the fourth hydrophilic resins as described above and carrying outdispersion operation by a prescribed disperser. As the disperser usedfor the dispersion, any disperser usually used for pigment dispersioncan be used without any problem. Examples of the disperser include apaint conditioner (manufactured by Red Devil, Inc.), a ball mill, apearl mill (both manufactured by Eirich GmbH), a sand mill, a viscomill, an atliter mill, a basket mill, a wet jet mill (all manufacturedby Genus Corporation), however it is preferable to select the dispersertaking dispersion performance and economy into consideration. Moreover,as a dispersion medium, a glass bead, a zirconia bead, an alumina bead,a magnetic bead, a stainless steel bead, or the like can be used.

In any of the first invention to the fourth invention, the hydrophilicresin composition in which 1 to 200 mass parts of Prussian blue relativeto 100 mass parts of the hydrophilic resin is blended as a dispersionratio of Prussian blue to the hydrophilic resin each constituting thehydrophilic resin composition is used. It is not preferable that thedispersion ratio of Prussian blue is less than 1 mass parts becausethere is a risk that the removal of radioactive cesium becomesinsufficient, and it is not preferable that the dispersion ratio ofPrussian blue exceeds 200 mass parts because mechanical properties ofthe composition become weak, the composition becomes inferior in waterresistance, and there is a risk that the composition cannot maintain theshape thereof in radiation-contaminated water.

In carrying out the method for removing radioactive cesium of the firstor the second present invention and the method for radioactive iodineand radioactive cesium of the third or the fourth present invention, itis preferable to use any one of the first to the fourth hydrophilicresin compositions comprising the above-described constitution in thefollowing form. Namely, the hydrophilic resin composition formed in afilm form obtained by applying release paper, a release film, or thelike with a solution of the hydrophilic resin composition so that athickness after drying becomes 5 to 100 μm, preferably 10 to 50 μm anddrying in a drying furnace is given as an example. In this case, thehydrophilic composition is used as a film for removing radioactivecesium released from the release paper/release film at the time of use.Moreover, besides the film form, a resin solution obtained from the rawmaterial described previously may be used by applying various basematerials with the resin solution or immersing various base materials inthe resin solution. As the base material in this case, a metal, glass,timber, fiber, various plastics, and so on can be used.

By immersing the film made of the first or the second hydrophilic resincomposition or the sheet obtained by applying various base materialswith the first or the second hydrophilic resin composition on variousbase materials, the film or the sheet obtained as described above, in aradioactive waste liquid, a waste liquid in which a radioactive solidmatter is decontaminated with water in advance, or the like, radioactivecesium present in these liquids can be removed. Moreover, against aradiation-contaminated solid matter or the like, the diffusion ofradioactive cesium can be prevented by covering the solid matter or thelike with the film or the sheet made of the first or the secondhydrophilic resin composition. As described previously, particularly inthe case where the second hydrophilic resin composition is used, thesecond hydrophilic resin composition is more useful in removingradioactive iodine because the water resistance of the film or the likeand the blocking resistance performance (sticking resistance) of thesurface can be realized.

Moreover, by immersing the film made of the third or the fourthhydrophilic resin composition or the sheet obtained by applying variousbase materials with the third or the fourth hydrophilic resincomposition, the film or the sheet obtained as described above, in aradioactive waste liquid, a waste liquid in which a radioactive solidmatter is decontaminated with water in advance, or the like, both ofradioactive iodine and radioactive cesium can selectively be removed.Moreover, against a radiation-contaminated solid matter or the like, thediffusion of radioactive iodine and radioactive cesium can be preventedby covering the solid matter with the film or the sheet made of thethird or the fourth hydrophilic resin composition.

The film or the sheet made of the first or the second hydrophilic resincomposition is insoluble to water and therefore can easily be taken outfrom the waste liquid after decontamination. Thereby, decontaminationcan be carried out simply and at low cost without the need for specialfacilities and electricity in removing radioactive cesium. Furthermore,the effect of volume reduction of radioactive waste can be expected bydrying the absorbed moisture and heating the film or the sheet at atemperature of 100 to 170° C. in the case of heating the film made ofthe first hydrophilic resin composition and 120 to 220° C. in the caseof heating the film made of the second hydrophilic resin compositionbecause the resin softens and the contraction of volume occurs.

Moreover, the film or the sheet made of the third or the fourthhydrophilic resin composition is insoluble to water and therefore caneasily be taken out from the waste liquid after decontamination. Therebydecontamination can be carried out simply and at low cost without theneed for special facilities and electricity in removing both ofradioactive iodine and radioactive cesium. Furthermore, the effect ofvolume reduction of radioactive waste can be expected by drying theabsorbed moisture and heating the film or the sheet at a temperature of100 to 170° C. because the resin softens and the contraction of volumeoccurs.

EXAMPLES

Next, the present invention will be described in more detail givingspecific Production Examples, Examples, and Comparative Examples,however the present invention is not limited to these examples.Moreover, “parts” and “%” in the following respective examples are basedon mass unless otherwise noted.

Examples and Comparative Examples with Regard to First Present Inventionand Second Present Invention Production Example 1-1 Synthesis ofHydrophilic Polyurethane Resin as First Hydrophilic Resin

A reaction vessel equipped with a stirrer, a thermometer, a gasintroducing tube, and a reflux cooler was purged with nitrogen, 150parts of polyethylene glycol (molecular weight 2,040) and 20 parts of1,4-butanediol were dissolved in a mixed solvent of 150 parts of methylethyl ketone (hereinafter, abbreviated as MEK) and 200 pars ofdimethylformamide (hereinafter, abbreviated as DMF) in the reactionvessel, and the resultant mixture was stirred well at 60° C. And asolution obtained by dissolving 77 parts of hydrogenated MDI in 50 partsof MEK was slowly dropped into the mixture under stirring. After thecompletion of the dropping, the resultant mixture was subjected toreaction at 80° C. for 7 hours, thereafter 60 parts of MEK was added tothe reaction mixture to obtain a hydrophilic resin solution to be usedin Example of the first present invention. The resin solution had aviscosity of 280 dPa·s (25° C.) at a solid content of 35%. Moreover, ahydrophilic resin film formed from the resin solution had a breakingstrength of 32.5 MPa, a breaking elongation of 450%, a thermal softeningtemperature of 115° C., and a weight average molecular weight of 78,000.

Production Example 1-2 Synthesis of Hydrophilic Polyurea Resin as FirstHydrophilic Resin

In a reaction vessel similar to the reaction vessel used in ProductionExample 1-1, 150 parts of polyethylene oxide diamine (“JEFFAMINE ED”(product name) manufactured by Huntsman Corporation; molecular weight2,000) and 18 parts of 1,4-diaminobutane were dissolved in 250 parts ofDMF. And a solution obtained by dissolving 73 parts of hydrogenated MDIin 100 parts of DMF was slowly dropped into the resultant mixture toreact while the resultant mixture was stirred well at an internaltemperature of 20 to 30° C. After the completion of the dropping, theinternal temperature was gradually raised, and when the internaltemperature reached 50° C., the resultant mixture was subjected toreaction for further 6 hours, thereafter 97 parts of DMF was added tothe reaction mixture to obtain a hydrophilic resin solution to be usedin Example of the first present invention. The resin solution had aviscosity of 210 dPa·s (25° C.) at a solid content of 35%. Moreover, ahydrophilic resin film formed from the resin solution had a breakingstrength of 18.3 MPa, a breaking elongation of 310%, a thermal softeningtemperature of 145° C., and a weight average molecular weight of 67,000.

Production Example 1-3 Synthesis of Hydrophilic Polyurethane-PolyureaResin as First Hydrophilic Resin

In a reaction vessel similar to the reaction vessel used in ProductionExample 1-1, 150 parts of polyethylene oxide diamine (“JEFFAMINE ED”(product name) manufactured by Huntsman Corporation; molecular weight2,000) and 15 parts of ethylene glycol were dissolved in 250 parts ofDMF. And a solution obtained by dissolving 83 parts of hydrogenated MDIin 100 parts of MEK was slowly dropped into the resultant mixture whilethe resultant mixture was stirred well at an internal temperature of 20to 30° C. After the completion of the dropping, the resultant mixturewas subjected to reaction at 80° C. for 6 hours, thereafter 110 parts ofMEK was added to the reaction mixture to obtain a hydrophilic resinsolution to be used in Example of the first present invention. The resinsolution had a viscosity of 250 dPa·s (25° C.) at a solid content of35%. Moreover, a hydrophilic resin film formed from the resin solutionhad a breaking strength of 14.7 MPa, a breaking elongation of 450%, athermal softening temperature of 121° C., and a weight average molecularweight of 71,000.

Production Example 2-1 Synthesis of Hydrophilic Polyurethane ResinHaving Polysiloxane Segment as Second Hydrophilic Resin

A reaction vessel equipped with a stirrer, a thermometer, a gasintroducing tube, and a reflux cooler was purged with nitrogen, and inthe reaction vessel, 8 parts of a polydimethylsiloxanepolyol having thefollowing structure (molecular weight 3,200), 142 parts of polyethyleneglycol (molecular weight 2,040), and 8 parts of ethylene glycol weredissolved in a mixed solvent of 150 parts of MEK and 140 parts of DMF.And a solution obtained by dissolving 52 parts of hydrogenated MDI in 50parts of MEK, was slowly dropped into the resultant mixture while theresultant mixture was stirred well at 60° C. After the completion of thedropping, the resultant mixture was subjected to reaction at 80° C. for6 hours, and thereafter 50 parts of MEK was added to the reactionmixture to obtain a solution of a hydrophilic polyurethane resin havinga structure specified in the second present invention.

The obtained resin solution had a viscosity of 410 dPa·s (25° C.) at asolid content of 35%. Moreover, a hydrophilic resin film formed from theresin solution had a breaking strength of 24.5 MPa, a breakingelongation of 450%, and a thermal softening temperature of 105° C.

Production Example 2-2 Synthesis of Hydrophilic Polyurea Resin HavingPolysiloxane Segment as Second Hydrophilic Resin

In a reaction vessel similar to the reaction vessel used in ProductionExample 2-1, 5 parts of a polydimethylsiloxanediamine having thefollowing structure (molecular weight 3,880), 145 parts of polyethyleneoxide diamine (“JEFFAMINE ED” (product name) manufactured by HuntsmanCorporation; molecular weight 2,000), and 8 parts of propylene diaminewere dissolved in 180 parts of dimethylformamide. And a solutionobtained by dissolving 47 parts of hydrogenated MDI in 100 parts of DMFwas slowly dropped into the resultant mixture to react while theresultant mixture was stirred well at an internal temperature of 10 to20° C. After the completion of the dropping, the internal temperaturewas gradually raised, and when the temperature reached 50° C., theresultant mixture was subjected to reaction for further 6 hours, andthereafter 100 parts of DMF was added to the reaction mixture to obtaina solution of a hydrophilic polyurea resin having a structure specifiedin the second present invention.

The obtained resin solution had a viscosity of 250 dPa·s (25° C.) at asolid content of 35%. Moreover, a film formed from the resin solutionhad a breaking strength of 27.6 MPa, a breaking elongation of 310%, anda thermal softening temperature of 145° C.

Production Example 2-3 Synthesis of Hydrophilic Polyurethane-PolyureaResin Having Polysiloxane Segment as Second Hydrophilic Resin

In a reaction vessel similar to the reaction vessel used in ProductionExample 2-1, 5 parts of a polydimethylsiloxanediamine (molecular weight3,880) used in Production Example 2-2, 145 parts of polyethylene glycol(molecular weight 2,040), and 8 parts of 1,3-butylene glycol weredissolved in a mixed solvent of 74 parts of toluene and 197 parts ofMEK. And a solution obtained by dissolving 42 parts of hydrogenated MDIin 100 parts of MEK was slowly dropped into the resultant mixture whilethe resultant mixture was stirred well at 60° C. After the completion ofthe dropping, the resultant mixture was subjected to reaction at 80° C.for 6 hours to obtain a solution of a hydrophilic polyurethane-polyurearesin having a structure specified in the second present invention. Theobtained resin solution had a viscosity of 200 dPa·s (25° C.) at a solidcontent of 35%. Moreover, a film formed from the resin solution had abreaking strength of 14.7 MPa, a breaking elongation of 450%, and athermal softening temperature of 90° C.

Production Example 4a Synthesis of Non-Hydrophilic Polyurethane Resin tobe Used in Comparative Example of First Present Invention and SecondPresent Invention

A reaction vessel similar to the reaction vessel used in ProductionExample 1-1 was purged with nitrogen, and in the reaction vessel, 150parts of polybutyleneadipate having an average molecular weight of about2,000 and 15 parts of 1,4-butanediol were dissolved in 250 parts of DMF.And a solution obtained by dissolving 62 parts of hydrogenated MDI in100 parts of MEK was slowly dropped into the resultant mixture while theresultant mixture was stirred well at 60° C. After the completion of thedropping, the resultant mixture was subjected to reaction at 80° C. for6 hours, and thereafter 71 parts of MEK was added to the reactionmixture to obtain a non-hydrophilic resin solution to be used inComparative Example of the first present invention and the secondpresent invention. The resin solution had a viscosity of 320 dPa·s (25°C.) at a solid content of 35%. Moreover, a non-hydrophilic resin filmformed from the solution had a breaking strength of 45 MPa, a breakingelongation of 480%, a thermal softening temperature of 110° C., and aweight average molecular weight of 82,000.

Production Example 5a Synthesis of Non-Hydrophilic Polyurethane-PolyureaResin to be Used in Comparative Example of First Present Invention andSecond Present Invention

A reaction vessel similar to the reaction vessel used in ProductionExample 1-1 was purged with nitrogen, and in the reaction vessel, 150parts of polybutyleneadipate having an average molecular weight of about2,000 and 18 parts of hexamethylenediamine were dissolved in 200 partsof DMF. And a solution obtained by dissolving 60 parts of hydrogenatedMDI in 100 parts of MEK was slowly dropped into the resultant mixturewhile the resultant mixture was stirred well at an internal temperatureof 20 to 30° C. After the completion of the dropping, the resultantmixture was subjected to reaction at 80° C. for 6 hours, and thereafter123 parts of MEK was added to the reaction mixture to obtain anon-hydrophilic resin solution to be used in Comparative Example of thefirst present invention and the second present invention. The resinsolution had a viscosity of 250 dPa·s (25° C.) at a solid content of35%. Moreover, a non-hydrophilic resin film formed from the resinsolution had a breaking strength of 14.7 MPa, a breaking elongation of450%, a thermal softening temperature of 121° C., and a weight averagemolecular weight of 68,000.

In Table 1, the property, the weight average molecular weights, and thecontent of the polysiloxane segment with regard to the respective resinsobtained by respective Production Examples are listed together.

TABLE 1 Properties of respective resins obtained by respectiveProduction Examples Weight Polysiloxane average segment Hydrophilic/molecular content Non-hydrophilic weight (%) Production Example 1-1Hydrophilic 78,000 Not contained Production Example 1-2 Hydrophilic67,000 Not contained Production Example 1-3 Hydrophilic 71,000 Notcontained Production Example 2-1 Hydrophilic 86,000 3.6 ProductionExample 2-2 Hydrophilic 71,000 2.3 Production Example 2-3 Hydrophilic65,000 2.4 Production Example 4a Non-hydrophilic 82,000 Not containedProduction Example 5a Non-hydrophilic 68,000 Not contained

Examples 1-1 to 1-3, Examples 2-1 to 2-3, and Comparative Examples 1 to2

Dispersion processing was applied for 24 hours by a ball mill with ahigh density alumina ball (3.5 g/ml) using each of the resin solutionsobtained by the above-described Production Examples and Prussian blue(Milori blue (color name); manufactured by Dainichiseika Color &Chemicals Mfg. Co., Ltd.) with the combination (based on mass) shown inTables 2-1 and 2-2. And the contents after the dispersion were taken outthrough a 100 mesh sieve made of a polyester resin to obtain each resincomposition comprising each resin solution and Prussian blue. The resincompositions of Examples and Comparative Examples with regard to thefirst present invention are shown in Table 2-1 together, and the resincompositions of Examples and Comparative Examples with regard to thesecond present invention are shown in Table 2-2 together.

TABLE 2-1 Preparation of resin compositions of Examples and ComparativeExamples with regard to the first present invention [mass parts]Comparative Comparative Example Example Example Example Example 1-1 1-21-3 1a 2a Resin solution of 100 Production Example 1-1 Resin solution of100 Production Example 1-2 Resin solution of 100 Production Example 1-3Resin solution of 100 Production Example 4a Resin solution of 100Production Example 5a Prussian blue 15 20 25 15 25 Solvent (MEK/DMF =7/3) 85 100 115 85 115

TABLE 2-2 Preparation of resin compositions of Examples and ComparativeExamples with regard to the second present invention [mass parts]Comparative Comparative Example Example Example Example Example 2-1 2-22-3 1a 2a Resin solution of 100 Production Example 2-1 Resin solution of100 Production Example 2-2 Resin solution of 100 Production Example 2-3Resin solution of 100 Production Example 4a Resin solution of 100Production Example 5a Prussian blue 15 20 25 15 25 Solvent (MEK/DMF =7/3) 85 100 115 85 115

[Evaluation of First Present Invention and Second Present Invention]

The following tests were carried out using each resin composition ofExamples and Comparative Examples of the second present invention tocheck the usefulness of each of the obtained resin compositions providedby the second present invention. Release paper was applied with eachresin composition having the formulation shown in Table 2-2 and dried at110° C. for 3 minutes to volatilize the solvent, and each resin filmhaving a thickness of about 20 μm was formed. The following items wereevaluated using each resin film thus obtained and formed from each resincomposition of Examples 2-1 to 2-3 and Comparative Examples 1a and 2a ofthe second present invention.

<Blocking Resistance (Sticking Resistance) of Resin Film>

Film faces of each resin film of Examples 2-1 to 2-3 and ComparativeExamples 1a and 2a formed from each resin composition were placed faceto face, thereafter the films were left at 40° C. for 1 day while a loadof 0.29 MPa was applied thereon. After that, the blocking property ofthe films with the faces placed face to face was visually observed andevaluated according to the following criteria. And the obtained resultsare shown in Table 3 together.

Good: No blocking property was observed.

Fair: The blocking property was slightly observed.

Poor: The blocking property was observed.

<Water Resistance of Resin Film>

Each film formed from each resin composition of Examples 2-1 to 2-3 andComparative Examples 1a and 2a was cut in a shape having a thickness of20 μm and a longitudinal length of 5 cm×a transversal length of 1 cm andimmersed in water having a temperature of 25° C. for 12 hours, and thewater resistance was evaluated by measuring the coefficient of expansionin the longitudinal direction of the immersed film. In addition, thecoefficient of expansion (expansion rate) was calculated by thefollowing method, and the water resistance was evaluated by rating afilm having a coefficient of expansion of 200% or less as “Good” and afilm having a coefficient of expansion of more than 200% as “Poor”. Theobtained results are shown in Table 3 together.

Coefficient of expansion(%)=(Longitudinal length after test/Originallongitudinal length)×100

TABLE 3 Evaluation results (blocking resistance and water resistance)Blocking Water resistance resistance (Coefficient of expansion (%))Example 2-1 Good Good (141) Example 2-2 Good Good (154) Example 2-3 GoodGood (163) Comparative Example 1a Poor Good (105) Comparative Example 2aPoor Good (103)

<Evaluation of Removal of Cesium>

A cesium-removing function of each of the obtained resin compositionsprovided by the first present invention and the second present inventionwas checked in the following manner. Using each resin composition ofExamples and Comparative Examples of the first present invention and thesecond present invention, release paper was applied with each resincomposition and dried at 110° C. for 3 minutes to volatilize thesolvent, and each resin film having a thickness of about 20 μm wasformed. The effect on the removal of cesium ion was evaluated by thefollowing method using each resin film of Examples and ComparativeExamples of the first present invention and the second present inventionthus obtained.

(Preparation of Cesium Solution for Evaluation Test>

A cesium solution for the evaluation test was prepared by dissolvingcesium chloride in ion exchanged pure water so that the solution had acesium ion concentration of 100 mg/L (100 ppm). In addition, when thecesium ion can be removed, radioactive cesium can be removed naturally.

Evaluation Results with Regard to Resin Composition of Example 1-1 ofFirst Present Invention

In 100 ml of the cesium solution prepared previously for the evaluationtest and having an ion concentration of 100 ppm, 20 g of the resin filmprepared using the hydrophilic resin composition of Example 1-1 wasimmersed (25° C.), and the cesium ion concentration in the solution wasmeasured by an ion chromatograph (IC2001 manufactured by TosohCorporation) every time a predetermined time was elapsed. In Table 4,the removing rate of the cesium ion in the solutions every time apredetermined time was elapsed was listed together with theconcentration of the cesium ion. Moreover, the obtained change of thecesium ion concentration with time is shown in FIG. 1.

Evaluation Results with Regard to Resin Compositions of Examples 1-2 and1-3 of First Present Invention

The cesium ion concentrations in the solutions every time apredetermined time was elapsed were measured in the same manner as inExample 1-1 except that 20 g of each resin film prepared by thehydrophilic resin composition of Example 1-2 or Example 1-3 was used foreach test. The obtained results are shown in Table 4 and FIG. 1 in thesame manner as in Example 1-1 described previously.

TABLE 4 Evaluation results in the case where the resin composition filmsof Examples 1-1 to 1-3 of the first present invention were used Example1-1 Example 1-2 Example 1-3 Immersion Cesium ion Cesium ion Cesium ionCesium ion Cesium ion Cesium ion time concentration removing rateconcentration removing rate concentration removing rate (Hr) (ppm) (%)(ppm) (%) (ppm) (%) 0 100.0 — 100.0 — 100.0 — 1 65.2 34.8 41.8 58.2 35.364.7 5 30.1 69.9 17.5 82.5 10.8 89.2 15 21.5 78.5 11.6 88.4 6.8 93.2 2416.8 83.2 7.3 92.7 5.2 94.8

Evaluation Results with regard to Resin Compositions of Examples 2-1 to2-3 of Second Present Invention

In 100 ml of the cesium solution, 20 g of each hydrophilic resincomposition film of Examples 2-1 to 2-3 was immersed (25° C.), and thecesium ion concentration in the solution was measured by an ionchromatograph (IC2001 manufactured by Tosoh Corporation) every time apredetermined time was elapsed. And the removing rate of the cesium ionin the solution was calculated. The results are shown in Table 5 andFIG. 2.

TABLE 5 Evaluation results in the case where the resin films of Examples2-1 to 2-3 of the second present invention were used Example 2-1 Example2-2 Example 2-3 Immersion Cesium ion Cesium ion Cesium ion Cesium ionCesium ion Cesium ion time concentration removing rate concentrationremoving rate concentration removing rate (Hr) (ppm) (%) (ppm) (%) (ppm)(%) 0 100.0 — 100.0 — 100.0 — 1 67.7 32.3 43.1 56.9 36.5 63.5 5 31.668.4 18.7 81.3 11.2 88.8 15 22.1 77.9 12.5 87.5 7.7 92.3 24 17.3 82.78.0 92.0 6.5 93.5

Evaluation Results with Regard to Resin Compositions of ComparativeExamples 1a and 2a of First Present Invention and Second PresentInvention

The cesium ion concentrations in the solutions were measured every timea predetermined time was elapsed in the same manner as in Example 1-1except that 20 g of each resin film prepared by the non-hydrophilicresin composition of Comparative Example 1a or 2a was used for eachtest. The obtained results are shown in Table 6 and FIG. 3 in the samemanner as in the case of Example 1-1 described previously. As clearlyunderstood from these results, the superiority of the removingperformance of the cesium ion in Examples of the first present inventionand the second present invention was confirmed.

TABLE 6 Evaluation results in the case where the resin composition filmsof Comparative Examples of 1a to 2a were used Comparative Example 1aComparative Example 2a Immersion Cesium ion Cesium ion Cesium ion Cesiumion time concentration removing concentration removing (Hr) (ppm) rate(%) (ppm) rate (%) 0 100.0 — 100.0 — 1 99.5 0.5 99.0 1.0 5 98.3 1.7 97.72.3 15 97.1 2.9 96.8 3.2 24 96.8 3.2 95.3 4.7

Examples and Comparative Examples with Regard to Third Present Inventionand Fourth Present Invention Production Example 3-1 Synthesis ofTertiary Amino Group-Containing Hydrophilic Polyurethane Resin as ThirdHydrophilic Resin

A reaction vessel equipped with a stirrer, a thermometer, a gasintroducing tube, and a reflux condenser was purged with nitrogen, 150parts of polyethylene glycol (molecular weight 2,040), 20 parts ofN-methyldiethanolamine, and 5 parts of diethylene glycol were dissolvedin a mixed solvent of 200 parts of MEK and 150 parts of DMF in thereaction vessel, and the resultant mixture was stirred well at 60° C.And a solution obtained by dissolving 74 parts of hydrogenated MDI in112 parts of MEK was slowly dropped into the mixture under stirring.After the completion of the dropping, the resultant mixture wassubjected to reaction at 80° C. for 6 hours to obtain a solution of ahydrophilic resin specified in the third present invention. The resinsolution had a viscosity of 530 dPa·s (25° C.) at a solid content of35%. Moreover, a hydrophilic resin film formed from the solution had abreaking strength of 24.5 MPa, a breaking elongation of 450%, and athermal softening temperature of 115° C.

Production Example 3-2 Synthesis of Tertiary Amino Group-ContainingHydrophilic Polyurea Resin as Third Hydrophilic Resin

In a reaction vessel similar to the reaction vessel used in ProductionExample 3-1, 150 parts of polyethylene oxide diamine (“JEFFAMINE ED”(product name) manufactured by Huntsman Corporation; molecular weight2,000), 30 parts of methyliminobispropylamine, and 4 parts of1,4-diamino butane were dissolved in 200 parts of DMF, and the resultantmixture was stirred well at an internal temperature of 20 to 30° C. Anda solution obtained by dissolving 83 parts of hydrogenated MDI in 100parts of DMF was slowly dropped into the resultant mixture understirring to react. After the completion of the dropping, the internaltemperature was gradually raised, and when the temperature reached 50°C., the resultant mixture was subjected to reaction for further 6 hours,and thereafter 195 parts of DMF was added to the reaction mixture toobtain a solution of a hydrophilic resin specified in the third presentinvention. The resin solution had a viscosity of 230 dPa·s (25° C.) at asolid content of 35%. Moreover, a hydrophilic resin film formed from theresin solution had a breaking strength of 27.6 MPa, a breakingelongation of 310%, and a thermal softening temperature of 145° C.

Production Example 3-3 Synthesis of Tertiary Amino Group-ContainingHydrophilic Polyurethane-Polyurea Resin as Third Hydrophilic Resin

In a reaction vessel similar to the reaction vessel used in ProductionExample 3-1, 150 parts of polyethylene oxide diamine (“JEFFAMINE ED”(product name) manufactured by Huntsman Corporation; molecular weight2,000), 30 parts ofN,N-dimethyl-N′,N′-dihydroxyethyl-1,3-diaminopropane, and 6 parts oftriethylene glycol were dissolved in 140 parts of DMF. And a solutionobtained by dissolving 70 parts of hydrogenated MDI in 200 parts of MEKwas slowly dropped into the resultant mixture while the resultantmixture was stirred well at an internal temperature of 20 to 30° C.After the completion of the dropping, the resultant mixture wassubjected to reaction at 80° C. for 6 hours, and thereafter 135 parts ofMEK was added to the reaction mixture to obtain a solution of ahydrophilic resin specified in the third present invention. The resinsolution had a viscosity of 280 dPa·s (25° C.) at a solid content of35%. Moreover, a hydrophilic resin film formed from the solution had abreaking strength of 14.7 MPa, a breaking elongation of 450%, and athermal softening temperature of 107° C.

Production Example 4-1 Synthesis of Hydrophilic Polyurethane ResinHaving Tertiary Amino Group and Polysiloxane Segment as FourthHydrophilic Resin

A reaction vessel equipped with a stirrer, a thermometer, a gasintroducing tube, and a reflux cooler was purged with nitrogen, and inthe reaction vessel, 8 parts of a polydimethylsiloxanepolyol having thefollowing structure (molecular weight 3,200), 142 parts of polyethyleneglycol (molecular weight 2,040), 20 parts of N-methyldiethanolamine, and5 parts of diethylene glycol were dissolved in a mixed solvent of 100parts of MEK and 200 parts of DMF. And a solution obtained by dissolving73 parts of hydrogenated MDI in 100 parts of MEK was slowly dropped intothe resultant mixture while the resultant mixture was stirred well at60° C. After the completion of the dropping, the resultant mixture wassubjected to reaction at 80° C. for 6 hours, and thereafter 60 parts ofMEK was added to the reaction mixture to obtain a solution of ahydrophilic polyurethane resin having a structure specified in thefourth present invention.

The obtained resin solution had a viscosity of 330 dPa·s (25° C.) at asolid content of 35%. Moreover, a hydrophilic resin film formed from thesolution had a breaking strength of 20.5 MPa, a breaking elongation of400%, and a thermal softening temperature of 103° C.

Production Example 4-2 Synthesis of Hydrophilic Polyurea Resin HavingTertiary Amino Group and Polysiloxane Segment as Fourth HydrophilicResin

In a reaction vessel similar to the reaction vessel used in ProductionExample 4-1, 5 parts of a polydimethylsiloxanediamine having thefollowing structure (molecular weight 3,880), 145 parts of polyethyleneoxide diamine (“JEFFAMINE ED” (product name) manufactured by HuntsmanCorporation; molecular weight 2,000), 25 parts ofmethyliminobispropylamine, and 5 parts of 1,4-diaminobutane weredissolved in 250 parts of DMF and the resultant mixture was stirred wellat an internal temperature of 20 to 30° C. And a solution obtained bydissolving 75 parts of hydrogenated MDI in 100 parts of DMF was slowlydropped into the resultant mixture under stirring to react. After thecompletion of the dropping, the internal temperature was graduallyraised, and when the temperature reached 50° C., the resultant mixturewas subjected to reaction for further 6 hours, and thereafter 124 partsof DMF was added to the reaction mixture to obtain a solution of ahydrophilic polyurea resin having a structure specified in the fourthpresent invention.

The obtained resin solution had a viscosity of 315 dPa·s (25° C.) at asolid content of 35%. Moreover, a hydrophilic resin film formed from theresin solution had a breaking strength of 31.3 MPa, a breakingelongation of 370%, and a thermal softening temperature of 147° C.Production Example 4-3

Synthesis of Hydrophilic Polyurethane-Polyurea Resin Having TertiaryAmino Group and Polysiloxane Segment as Fourth Hydrophilic Resin

In a reaction vessel similar to the reaction vessel used in ProductionExample 4-1, 5 parts of an ethylene oxide added typepolydimethylsiloxane having the following structure (molecular weight4,500), 145 parts of polyethylene oxide diamine (“JEFFAMINE ED” (tradename) manufactured by Huntsman Corporation; molecular weight 2,000), 30parts of N,N-dimethyl-N′,N′-dihydroxyethyl-1,3-diaminopropane, and 5parts of 1,4-diaminobutane were dissolved in a mixed solvent of 150parts of MEK and 150 parts of DMF, and the resultant mixture was stirredwell at an internal temperature of 20 to 30° C. And a solution obtainedby dissolving 72 parts of hydrogenated MDI in 100 parts of MEK wasslowly dropped into the resultant mixture under stirring. After thecompletion of the dropping, the resultant mixture was subjected toreaction at 80° C. for 6 hours, and after the completion of thereaction, 75 parts of MEK was added to the reaction mixture to obtain asolution of a hydrophilic polyurethane-polyurea resin having a structurespecified in the fourth present invention.

The obtained resin solution had a viscosity of 390 dPa·s (25° C.) at asolid content of 35%. Moreover, a hydrophilic resin film formed from theresin solution had a breaking strength of 22.7 MPa, a breakingelongation of 450%, and a thermal softening temperature of 127° C.

Production Example 4b Synthesis of Non-Hydrophilic Polyurethane Resinnot Containing Tertiary Amino Group and Polysiloxane Segment to be Usedin Comparative Example of Third Present Invention and Fourth PresentInvention

A reaction vessel similar to the reaction vessel used in ProductionExample 3-1 was purged with nitrogen, and 150 parts ofpolybutyleneadipate having an average molecular weight of about 2,000and 15 parts of 1,4-butanediol were dissolved in 250 parts of DMF in thereaction vessel. And a solution obtained by dissolving 62 parts ofhydrogenated MDI in 171 parts of DMF was slowly dropped into theresultant mixture while the resultant mixture was stirred well at 60° C.After the completion of the dropping, the resultant mixture wassubjected to reaction at 80° C. for 6 hours to obtain a resin solutionto be used in Comparative Example. The resin solution had a viscosity of3.2 MPa·s (25° C.) at a solid content of 35%. A non-hydrophilic resinfilm obtained from the resin solution had a breaking strength of 45 MPa,a breaking elongation of 480%, and a thermal softening temperature of110° C.

Production Example 5b Synthesis of Tertiary Amino Group-ContainingNon-Hydrophilic Polyurethane Resin to be Used in Comparative Example ofThird Present Invention and Fourth Present Invention

A reaction vessel similar to the reaction vessel used in ProductionExample 3-1 was purged with nitrogen, and 150 parts ofpolybutyleneadipate having an average molecular weight of about 2,000,20 parts of N-methyldiethanolamine, and 5 parts of ethylene glycol weredissolved in a mixed solvent of 200 parts of MEK and 150 parts of DMF inthe reaction vessel. And a solution obtained by dissolving 74 parts ofhydrogenated MDI in 112 parts of MEK was slowly dropped into theresultant mixture while the resultant mixture was stirred well at 60° C.After the completion of the dropping, the resultant mixture wassubjected to reaction at 80° C. for 6 hours to obtain a resin solutionto be used in Comparative Example. The resin solution had a viscosity of510 dPa·s (25° C.) at a solid content of 35%. Moreover, anon-hydrophilic resin film formed from the resin solution had a breakingstrength of 23.5 MPa, a breaking elongation of 470%, and a thermalsoftening temperature of 110° C.

In Table 7-1, the properties with regard to the respective resins to beused in Examples of the third present invention obtained by theabove-described Production Examples 3-1 to 3-3 and respective resins tobe used in Comparative Examples of the third present invention obtainedby Production Examples 4b and 5b are listed together. Specifically asthe properties, the evaluation of hydrophilicity, the weight averagemolecular weight, and the content of the tertiary amino group(equivalent) per 1,000 molecular weight are shown.

TABLE 7-1 Properties of respective resins obtained by respectiveProduction Examples relating to the third present invention Tertiaryamino Hydrophilic/ Weight average group equivalent Non-hydrophilicmolecular weight (eq/kg) Production Hydrophilic 87,000 0.67 Example 3-1Production Hydrophilic 63,000 0.76 Example 3-2 Production Hydrophilic69,000 1.23 Example 3-3 Production Non-hydrophilic 72,000 Not containedExample 4b Production Non-hydrophilic 84,000 0.68 Example 5b

In Table 7-2, the properties with regard to the respective resins to beused in Examples of the fourth present invention obtained by theabove-described Production Examples 4-1 to 4-3 and respective resins tobe used in Comparative Examples of the fourth present invention obtainedby Production Examples 4b and 5b are listed together. Specifically, theevaluation of hydrophilicity, the weight average molecular weight, andthe content of the tertiary amino group (equivalent) per 1,000 molecularweight are shown.

TABLE 7-2 Properties of respective resins of respective ProductionExamples relating to the fourth present invention Weight Tertiaryaverage amino group Polysiloxane Hydrophilic/ molecular equivalentsegment Non-hydrophilic weight (eq/kg) content (%) ProductionHydrophilic 75,000 0.66 3.2 Example 4-1 Production Hydrophilic 71,0000.75 2.0 Example 4-2 Production Hydrophilic 77,000 1.22 1.2 Example 4-3Production Non-hydrophilic 72,000 Not Not Example 4b contained containedProduction Non-hydrophilic 84,000 0.68 Not Example 5b contained

Examples 3-1 to 3-3 and Comparative Examples 1b to 2 b of Third PresentInvention

Dispersion processing was applied for 24 hours by a ball mill with ahigh density alumina ball (3.5 g/ml) using each of the resin solutionsobtained by the above-described Production Examples 3-1 to 3-3,4-b, and5b and Prussian blue (Milori blue (color name); manufactured byDainichiseika Color & Chemicals Mfg. Co., Ltd.) with the combination(based on mass) shown in Table 8-1. And the contents after thedispersion were taken out through a 100 mesh sieve made of a polyesterresin to obtain each resin composition comprising a resin solution andPrussian blue.

TABLE 8-1 Preparation of resin Compositions of Examples and ComparativeExamples with regard to the third present invention [mass parts] Compar-Compar- Exam- Exam- Exam- ative ative ple ple ple Example Example 3-13-2 3-3 1b 2b Resin solution 100 of Production Example 3-1 Resinsolution 100 of Production Example 3-2 Resin solution 100 of ProductionExample 3-3 Resin solution 100 of Production Example 4b Resin solution100 of Production Example 5b Prussian blue 15 20 25 15 25 Solvent 85 100115 85 115 (MEK/DMF = 7/3)

Examples 4-1 to 4-3 and Comparative Examples 1b to 2 b of Fourth PresentInvention

Dispersion processing was applied for 24 hours by a ball mill with ahigh density alumina ball (3.5 g/ml) using each of the resin solutionsobtained by the above-described Production Examples 4-1 to 4-3,4-b, and5b and Prussian blue (Milori blue (color name); manufactured byDainichiseika Color & Chemicals Mfg. Co., Ltd.) with the combination(based on mass) shown in Table 8-2. And the contents after thedispersion were taken out through a 100 mesh sieve made of a polyesterresin to obtain each resin composition comprising a resin solution andPrussian blue.

TABLE 8-2 Preparation of resin Compositions of Examples and ComparativeExamples with regard to the fourth present invention [mass parts]Compar- Compar- Exam- Exam- Exam- ative ative ple ple ple ExampleExample 4-1 4-2 4-3 1b 2b Resin solution 100 of Production Example 4-1Resin solution 100 of Production Example 4-2 Resin solution 100 ofProduction Example 4-3 Resin solution 100 of Production Example 4b Resinsolution 100 of Production Example 5b Prussian blue 15 20 25 15 25Solvent 85 100 115 85 115 (MEK/DMF = 7/3)

Evaluation of Third Present Invention and Fourth Present Invention

The following tests were carried out using each resin composition ofExamples and Comparative Examples of the fourth present invention tocheck the usefulness of each of the obtained resin compositions providedby the fourth present invention. Release paper was applied with eachresin composition having the formulation shown in Table 8-2 and dried at110° C. for 3 minutes to volatilize the solvent, and each resin filmhaving a thickness of about 20 μm was formed. The following items wereevaluated using each resin film thus obtained and formed from each resincomposition of Examples 4-1 to 4-3 and Comparative Examples 1b and 2b ofthe fourth present invention.

<Blocking Resistance (Sticking Resistance)>

Film faces of each resin film of Examples 4-1 to 4-3 and ComparativeExamples 1b and 2b formed from each resin composition were placed faceto face, thereafter the films were left at 40° C. for 1 day while a loadof 0.29 MPa was applied thereon. After that, the blocking property ofthe films with the faces placed face to face was visually observed andevaluated according to the following criteria. And the obtained resultsare shown in Table 9 together.

Good: No blocking property was observed.

Fair: The blocking property was slightly observed.

Poor: The blocking property was observed.

<Water Resistance>

Each film formed from each resin composition of Examples 4-1 to 4-3 andComparative Examples 1b and 2b was cut in a shape having a thickness of20 μm and a longitudinal length of 5 cm×a transversal length of 1 cm andimmersed in water having a temperature of 25° C. for 12 hours, and thecoefficient of expansion (%) in the longitudinal direction of theimmersed film was measured and calculated using the following equation.And the water resistance was evaluated by rating a film having acoefficient of expansion of 200% or less as “Good” and a film having acoefficient of expansion of more than 200% as “Poor”. The obtainedresults are shown in Table 9.

Coefficient of expansion(%)=(Longitudinal length after test/Originallongitudinal length)×100

TABLE 9 Evaluation results (blocking resistance and water resistance)Blocking Water resistance resistance (Coefficient of expansion (%))Example 4-1 Good Good (131) Example 4-2 Good Good (140) Example 4-3 GoodGood (153) Comparative Example 1b Poor Good (105) Comparative Example 2bFair Good (103)

<Effect on Removal of Iodine Ion and Cesium Ion>

An iodine ion and cesium ion-removing function of each of the obtainedresin compositions provided by the third present invention and thefourth present invention was checked in the following manner. Using eachresin composition of Examples and Comparative Examples of the thirdpresent invention and the fourth present invention, release paper wasapplied with each resin composition and dried at 110° C. for 3 minutesto volatilize the solvent, and each resin film having a thickness ofabout 20 μm was formed. The effect on the removal of an iodine ion and acesium ion was evaluated by the following method using each resin filmthus obtained and formed from each resin composition of Examples andComparative Examples of the third present invention and the fourthpresent invention.

(Preparation of Iodine Solution and Cesium Solution for Evaluation Test>

An iodine solution for the evaluation test was prepared by dissolvingpotassium iodide in ion exchanged pure water so that the solution had aniodine ion concentration of 200 mg/L (200 ppm). Moreover, a cesiumsolution for the evaluation test was prepared by dissolving cesiumchloride in ion exchanged pure water so that the solution had a cesiumion concentration of 200 mg/L (200 ppm). In addition, when the iodineion and the cesium ion can be removed, radioactive iodine andradioactive cesium can be removed naturally.

(Evaluation Results with Regard to Resin Composition of Example 3-1 ofThird Present Invention

In a mixed solution of 50 ml of the iodine solution prepared for theevaluation test previously and 50 ml of the cesium solution prepared forthe evaluation test previously, 20 g of the resin film prepared usingthe hydrophilic resin composition of Example 3-1 was immersed (25° C.),and the iodine ion concentration and the cesium ion concentration in thesolution were measured by an ion chromatograph (IC2001 manufactured byTosoh Corporation) every time a predetermined time was elapsed. Themeasurement results are shown in Table 10. And it was confirmed that, asshown in Table 10, both of the iodine ion concentration and the cesiumion concentration in the solution were decreased every time apredetermined time was elapsed. The removing rates of the iodine ion andthe cesium ion in the solution every time a predetermined time iselapsed are listed together with the iodine ion concentration and thecesium ion concentration. Moreover, the results are shown in FIG. 4 andFIG. 5.

TABLE 10 Evaluation results in the case where the resin composition filmof Example 3-1 of the third present invention was used Iodine ion Cesiumion Immersion Concentration Removing Concentration Removing time insolution rate in solution rate (Hr) (ppm) (%) (ppm) (%) 0 100.0 — 100.0— 1 55.3 44.7 60.2 39.8 5 25.1 74.9 27.6 72.4 15 15.3 84.7 19.2 80.8 2411.1 88.9 15.1 84.9

Evaluation Results with Regard to Resin Composition of Example 3-2 ofThird Present Invention

The iodine ion concentration and the cesium ion concentration in thesolution every time a predetermined time was elapsed were measured inthe same manner as in the case where the resin film prepared using thehydrophilic resin composition of Example 3-1 was used except that 20 gof the resin film prepared by the hydrophilic resin composition ofExample 3-2 was used. The obtained results are shown in Table 11, FIG.4, and FIG. 5 in the same manner as in the case of Example 3-1 describedpreviously.

TABLE 11 Evaluation results in the case where the resin composition filmof Example 3-2 of the third present invention was used Iodine ion Cesiumion Immersion Concentration Removing Concentration Removing time insolution rate in solution rate (Hr) (ppm) (%) (ppm) (%) 0 100.0 — 100.0— 1 51.5 48.5 51.2 48.8 5 20.7 79.3 20.8 79.2 15 11.7 88.3 13.3 86.7 249.4 90.6 10.8 89.2

Evaluation Results with Regard to Resin Composition of Example 3-3 ofThird Present Invention

The iodine ion concentration and the cesium ion concentration in thesolution every time a predetermined time was elapsed were measured inthe same manner as in the case where the resin film prepared using thehydrophilic resin composition of Example 3-1 was used except that 20 gof the resin film prepared by the hydrophilic resin composition ofExample 3-3 was used. The obtained results are shown in Table 12, FIG.4, and FIG. 5 in the same manner as in the case of Example 3-1 describedpreviously.

TABLE 12 Evaluation results in the case where the resin composition filmof Example 3-3 of the third present invention was used Iodine ion Cesiumion Immersion Concentration Removing Concentration Removing time insolution rate in solution rate (Hr) (ppm) (%) (ppm) (%) 0 100.0 — 100.0— 1 48.3 51.7 40.2 59.8 5 17.8 82.2 12.3 87.7 15 9.7 90.3 8.1 91.9 246.8 93.2 7.8 92.2

Evaluation Results with Regard to Resin Composition of Example 4-1 ofFourth Present Invention

In a mixed solution of 50 ml of the iodine solution prepared for theevaluation test previously and 50 ml of the cesium solution prepared forthe evaluation test previously, 20 g of the resin film prepared usingthe hydrophilic resin composition of Example 4-1 was immersed (25° C.),and the iodine ion concentration and the cesium ion concentration in thesolution were measured by an ion chromatograph (IC2001 manufactured byTosoh Corporation) every time a predetermined time was elapsed. Theresults are shown in Table 13. And it was confirmed that, as shown inTable 13, both of the iodine ion concentration and the cesium ionconcentration in the solution were decreased every time a predeterminedtime was elapsed. The removing rates of the iodine ion and the cesiumion in the solution every time a predetermined time is elapsed arelisted together with the iodine ion concentration and the cesium ionconcentration. Moreover, the results are shown in FIG. 6 and FIG. 7.

TABLE 13 Evaluation results in the case where the resin composition filmof Example 4-1 of the fourth present invention was used Iodine ionCesium ion Immersion Concentration Removing Concentration Removing timein solution rate in solution rate (Hr) (ppm) (%) (ppm) (%) 0 100.0 —100.0 — 1 68.5 31.5 62.7 37.3 5 38.1 61.9 30.1 69.9 15 23.2 76.8 21.878.2 24 19.8 80.2 16.8 83.2

Evaluation Results with Regard to Resin Composition of Example 4-2 ofFourth Present Invention

The iodine ion concentration and the cesium ion concentration in thesolution every time a predetermined time was elapsed were measured inthe same manner as in the case where the resin film prepared using thehydrophilic resin composition of Example 4-1 was used except that 20 gof the resin film prepared using the hydrophilic resin composition ofExample 4-2 was used. The obtained results are shown in Table 14, FIG.6, and FIG. 7 in the same manner as in the case of Example 4-1 describedpreviously. As a result thereof, it was confirmed that both of theiodine ion concentration and the cesium ion concentration in thesolution were decreased every time a predetermined time was elapsed alsoin the case where the hydrophilic resin solution of Example 4-2 wasused.

TABLE 14 Evaluation results in the case where the resin composition filmof Example 4-2 of the fourth present invention was used Iodine ionCesium ion Immersion Concentration Removing Concentration Removing timein solution rate in solution rate (Hr) (ppm) (%) (ppm) (%) 0 100.0 —100.0 — 1 60.0 40.0 53.1 46.9 5 30.5 69.5 21.9 78.1 15 16.3 83.7 15.284.8 24 14.8 85.2 11.8 88.2

Evaluation Results with Regard to Resin Composition of Example 4-3 ofFourth Present Invention

The iodine ion concentration and the cesium ion concentration in thesolution every time a predetermined time was elapsed were measured inthe same manner as in the case where the resin film prepared using thehydrophilic resin composition of Example 4-1 was used except that 20 gof the resin film prepared by the hydrophilic resin composition ofExample 4-3 was used. The obtained results are shown in Table 15, FIG.6, and FIG. 7 in the same manner as in the case of Example 4-1 describedpreviously. As a result thereof, it was confirmed that both of theiodine ion concentration and the cesium ion concentration in thesolution were decreased every time a predetermined time was elapsed alsoin the case where the hydrophilic resin solution of Example 4-3 wasused.

TABLE 15 Evaluation results in the case where the resin composition filmof Example 4-3 of the fourth present invention was used Iodine ionCesium ion Immersion Concentration Removing Concentration Removing timein solution rate in solution rate (Hr) (ppm) (%) (ppm) (%) 0 100.0 —100.0 — 1 52.7 47.3 41.9 58.1 5 22.5 77.5 13.1 86.9 15 12.8 87.2 9.091.0 24 10.3 89.7 7.2 92.8

Evaluation Results with Regard to Resin Composition of ComparativeExample 1b of Third Present Invention and Fourth Present Invention

The iodine ion concentration and the cesium ion concentration in thesolution were measured every time a predetermined time was elapsed inthe same manner as in the case where the resin film prepared using thehydrophilic resin composition of Example 4-1 except that 20 g of theresin film prepared by the non-hydrophilic resin composition ofComparative Example 1b was used. The obtained results are shown in Table16, FIG. 8, and FIG. 9 in the same manner as in the case of Example 4-1described previously. As clearly understood from these results, thesuperiority of the removing performance of the iodine ion and the cesiumion in Examples of the third present invention and the fourth presentinvention was confirmed.

TABLE 16 Evaluation results in the case where the resin composition filmof Comparative Example 1b was used Iodine ion Cesium ion ImmersionConcentration Removing Concentration Removing time in solution rate insolution rate (Hr) (ppm) (%) (ppm) (%) 0 100.0 — 100.0 — 1 98.2 1.8 99.10.9 5 98.5 1.5 98.7 1.3 15 97.6 2.4 96.5 1.5 24 97.1 2.9 98.4 1.6

Evaluation Results with Regard to Resin Composition of ComparativeExample 2b of Third Present Invention and Fourth Present Invention

The iodine ion concentration and the cesium ion concentration in thesolution were measured every time a predetermined time was elapsed inthe same manner as in the case where the resin film prepared using thehydrophilic resin composition of Example 4-1 except that 20 g of a resinfilm prepared by the non-hydrophilic resin composition of ComparativeExample 2b was used. The obtained results are shown in Table 17, FIG. 8,and FIG. 9 in the same manner as in the case of Example 4-1 describedpreviously. As clearly understood from these results, the superiority ofthe removing performance of the iodine ion and cesium ion in Examples ofthe third present invention and the fourth present invention wasconfirmed.

TABLE 17 Evaluation results in the case where the resin composition filmof Comparative Example 2b was used Iodine ion Cesium ion ImmersionConcentration Removing Concentration Removing time in solution rate insolution rate (Hr) (ppm) (%) (ppm) (%) 0 100.0 — 100.0 — 1 97.1 2.9 98.91.1 5 95.3 4.7 98.1 1.9 15 94.7 5.3 97.8 2.2 24 93.8 6.2 97.1 2.9

INDUSTRIAL APPLICABILITY

As an application example of the first present invention and the secondpresent invention, radioactive cesium in liquid and/or a solid mattercan be processed simply and at low cost, furthermore the removingprocessing of radioactive cesium can be applied without the need for anenergy source such as electricity, therefore it becomes possible toremove a radioactive substance present in liquid or a solid matter whichradioactive substance has been a problem recently simply andeconomically by carrying out the novel method for removing radioactivecesium, and thus the utilization can be expected.

Particularly, by the technique of the first present invention, theremoved radioactive cesium is quickly taken in the first hydrophilicresin composition comprising: a first hydrophilic resin having ahydrophilic segment; and a metal ferrocyanide compound a representativeexample of which is Prussian blue and can stably be immobilized,furthermore since the main component of the first hydrophilic resincomposition is a resin composition, the volume reduction of radioactivewaste can be achieved as necessary, therefore the problem thatradioactive waste produced after the removing processing of radioactivesubstances becomes huge can be reduced, the practical value is extremelyhigh, and the utilization can be expected.

Moreover, by the second present invention, it becomes possible torealize, in addition to the effect obtained by the above-described firstpresent invention, the water resistance and the blocking resistance(sticking resistance) of the surface brought about by the presence of apolysiloxane segment by introducing the polysiloxane segment in thestructure of the second hydrophilic resin having a hydrophilic segment,and therefore the utilization can be expected from the point ofrealizing the water resistance and the blocking resistance.

As an application example of the third present invention and the fourthpresent invention, radioactive iodine and radioactive cesium in aradioactive waste liquid and/or a radioactive solid matter can beremoved simply and at low cost, and furthermore without the need for anenergy source such as electricity, therefore it becomes possible toremove radioactive substances present in a mixed state in liquid or asolid matter which radioactive substances have been a problem recentlysimply and economically by carrying out the novel method forsimultaneously removing radioactive iodine and radioactive cesium, andthus the practical value is extremely high.

Particularly, by the technique of the third present invention, theremoved radioactive iodine and radioactive cesium are taken in the thirdhydrophilic resin composition comprising: a third hydrophilic resinhaving a particular structure; and Prussian blue and can stably beimmobilized, furthermore since the main component of the thirdhydrophilic resin composition is a resin composition, the volumereduction of radioactive waste can be achieved as necessary, thereforethe problem in large amounts of radioactive waste produced after theremoving processing of radioactive substances can be reduced, and theutilization can be expected.

Moreover, by the fourth present invention, it becomes possible torealize, in addition to the effect obtained by the above-described thirdpresent invention, the water resistance and the blocking resistance(sticking resistance) of the resin surface brought about by the presenceof a polysiloxane segment and to improve the practicability in the casewhere the removing processing is applied using the film or the like byusing the fourth hydrophilic resin composition comprising a fourthhydrophilic resin introducing, in addition to a hydrophilic segment anda tertiary amino group forming an ion bond with radioactive iodine, apolysiloxane segment further in the structure thereof, therefore theproblem in radioactive waste produced after the removing processing ofradioactive substances can be reduced, and the utilization can beexpected.

1. A method for removing radioactive cesium applying removing processingto radioactive cesium in a radioactive waste liquid and/or a radioactivesolid matter using a hydrophilic resin composition comprising ahydrophilic resin and a metal ferrocyanide compound, wherein thehydrophilic resin composition comprises at least one hydrophilic resinselected from the group consisting of a hydrophilic polyurethane resin,a hydrophilic polyurea resin, and a hydrophilic polyurethane-polyurearesin each having a hydrophilic segment; and the metal ferrocyanidecompound is dispersed in the hydrophilic resin composition in a ratio ofat least 1 to 200 mass parts relative to 100 mass parts of thehydrophilic resin.
 2. A method for removing radioactive cesium applyingremoving processing to radioactive cesium present in a radioactive wasteliquid and/or a radioactive solid matter using a hydrophilic resincomposition comprising a hydrophilic resin and a metal ferrocyanidecompound, wherein the hydrophilic resin comprises at least one selectedfrom the group consisting of a hydrophilic polyurethane resin, ahydrophilic polyurea resin, and a hydrophilic polyurethane-polyurearesin each having a hydrophilic segment and further each having, in themain chain and/or a side chain in the structure thereof, a polysiloxanesegment; and the hydrophilic resin composition comprises the metalferrocyanide compound dispersed therein in a ratio of at least 1 to 200mass parts relative to 100 mass parts of the hydrophilic resin.
 3. Themethod for removing radioactive cesium according to claim 2, wherein thehydrophilic resin is a resin formed from, as a part of a raw material, acompound having at least one active hydrogen-containing group and apolysiloxane segment in the same molecule.
 4. The method for removingradioactive cesium according to claim 1, wherein the hydrophilic segmentis a polyethylene oxide segment.
 5. The method for removing radioactivecesium according to claim 1, wherein the metal ferrocyanide compound isa compound represented by the following general formula (1):A_(x)M_(y)[Fe(CN)₆]  (1) [in the formula, A is any one selected from K,Na, and NH₄, M is any one selected from Ca, Mn, Fe, Co, Ni, Cu, and Zn,x and y satisfy an equation x+ny=4 (x is an integer from 0 to 3), and nrepresents a valence number of M].
 6. A hydrophilic resin compositionfor removing radioactive cesium exhibiting a function capable ofimmobilizing radioactive cesium in liquid and/or a solid matter, whereinthe hydrophilic resin composition comprises a hydrophilic resin and ametal ferrocyanide compound; the hydrophilic resin is at least one resinselected from the group consisting of a hydrophilic polyurethane resin,a hydrophilic polyurea resin, and a hydrophilic polyurethane-polyurearesin each having a hydrophilic segment and each obtained by reacting anorganic polyisocyanate with a high-molecular weight hydrophilic polyoland/or polyamine being a hydrophilic component, the resin beinginsoluble to water and hot water; and the metal ferrocyanide compound isdispersed in the hydrophilic resin composition in a ratio of at least 1to 200 mass parts relative to 100 mass parts of the hydrophilic resin.7. A hydrophilic resin composition for removing radioactive cesiumexhibiting a function capable of immobilizing radioactive cesium inliquid and/or a solid matter, wherein the hydrophilic resin compositioncomprises a hydrophilic resin and a metal ferrocyanide compound; thehydrophilic resin is a resin having a hydrophilic segment and apolysiloxane segment and obtained by reacting, as a part of a rawmaterial, a compound having at least one active hydrogen-containinggroup and a polysiloxane segment in the same molecule, the resin beinginsoluble to water and hot water; and the metal ferrocyanide compound isdispersed in the hydrophilic resin composition in a ratio of at least 1to 200 mass parts relative to 100 mass parts of the hydrophilic resin.8. A hydrophilic resin composition for removing radioactive cesiumexhibiting a function capable of immobilizing radioactive cesium inliquid and/or a solid matter, wherein the hydrophilic resin compositioncomprises a hydrophilic resin and a metal ferrocyanide compound; thehydrophilic resin is at least one selected from the group consisting ofa hydrophilic polyurethane resin, a hydrophilic polyurea resin, and ahydrophilic polyurethane-polyurea resin each having a hydrophilicsegment, further each having, in the main chain and/or a side chain inthe structure thereof, a polysiloxane segment, and each obtained byreacting an organic polyisocyanate, a high molecular weight polyoland/or polyamine being a hydrophilic component, and a compound having atleast one active hydrogen-containing group and a polysiloxane segment inthe same molecule; and the metal ferrocyanide compound is dispersed inthe hydrophilic resin composition in a ratio of at least 1 to 200 massparts relative to 100 mass parts of the hydrophilic resin.
 9. Thehydrophilic resin composition for removing radioactive cesium accordingto claim 6, wherein the hydrophilic segment of the hydrophilic resin isa polyethylene oxide segment.
 10. The hydrophilic resin composition forremoving radioactive cesium according to claim 6, wherein the metalferrocyanide compound is a compound represented by the following generalformula (1):A_(x)M_(y)[Fe(CN)₆]  (1) [in the formula, A is any one selected from K,Na, and NH₄, M is any one selected from Ca, Mn, Fe, Co, Ni, Cu, and Zn,x and y satisfy an equation x+ny=4 (x is an integer from 0 to 3), and nrepresents a valence number of M].
 11. A method for removing radioactiveiodine and radioactive cesium applying removing processing to both ofradioactive iodine and radioactive cesium present in a radioactive wasteliquid and/or a radioactive solid matter using a hydrophilic resincomposition comprising a hydrophilic resin and a metal ferrocyanidecompound, wherein the hydrophilic resin comprises at least one selectedfrom the group consisting of a hydrophilic polyurethane resin, ahydrophilic polyurea resin, and a hydrophilic polyurethane-polyurearesin each having a hydrophilic segment and further each having, in themain chain and/or a side chain in the structure thereof, a tertiaryamino group; and the hydrophilic resin composition comprises the metalferrocyanide compound dispersed therein in a ratio of at least 1 to 200mass parts relative to 100 mass parts of the hydrophilic resin.
 12. Themethod for removing radioactive iodine and radioactive cesium accordingto claim 11, wherein the hydrophilic resin is a resin formed from, as apart of a raw material, a polyol having at least one tertiary aminogroup or a polyamine having at least one tertiary amino group.
 13. Amethod for removing radioactive iodine and radioactive cesium applyingremoving processing to both of radioactive iodine and radioactive cesiumpresent in a radioactive waste liquid and/or a radioactive solid matterusing a hydrophilic resin composition comprising a hydrophilic resin anda metal ferrocyanide compound, wherein the hydrophilic resin comprisesat least one selected from the group consisting of a hydrophilicpolyurethane resin, a hydrophilic polyurea resin, and a hydrophilicpolyurethane-polyurea resin each having a hydrophilic segment andfurther each having, in the main chain and/or a side chain in thestructure thereof, a tertiary amino group and a polysiloxane segment;and the hydrophilic resin composition comprises the metal ferrocyanidecompound dispersed therein in a ratio of at least 1 to 200 mass partsrelative to 100 mass parts of the hydrophilic resin.
 14. The method forremoving radioactive iodine and radioactive cesium according to claim13, wherein the hydrophilic resin is a resin formed from, as a part of araw material, a polyol having at least one tertiary amino group or apolyamine having at least one tertiary amino group and a compound havingat least one active hydrogen-containing group and a polysiloxane segmentin the same molecule.
 15. The method for removing radioactive iodine andradioactive cesium according to claim 11, wherein the hydrophilicsegment is a polyethylene oxide segment.
 16. The method for removingradioactive iodine and radioactive cesium according to claim 11, whereinthe metal ferrocyanide compound is a compound represented by thefollowing general formula (1):A_(x)M_(y)[Fe(CN)₆]  (1) [in the formula, A is any one selected from K,Na, and NH₄, M is any one selected from Ca, Mn, Fe, Co, Ni, Cu, and Zn,x and y satisfy an equation x+ny=4 (x is an integer from 0 to 3), and nrepresents a valence number of M].
 17. A hydrophilic resin compositionfor removing radioactive iodine and radioactive cesium exhibiting afunction capable of immobilizing both of radioactive iodine andradioactive cesium in liquid and/or a solid matter, wherein thehydrophilic resin composition comprises a hydrophilic resin and a metalferrocyanide compound; the hydrophilic resin is a resin having ahydrophilic segment, having, in the molecular chain, a tertiary aminogroup, and formed from, as a part of a raw material, a polyol having atleast one tertiary amino group or a polyamine having at least onetertiary amino group, the resin being insoluble to water and hot water;and the metal ferrocyanide compound is dispersed in the hydrophilicresin composition in a ratio of at least 1 to 200 mass parts relative to100 mass parts of the hydrophilic resin.
 18. A hydrophilic resincomposition for removing radioactive iodine and radioactive cesiumexhibiting a function capable of immobilizing both of radioactive iodineand radioactive cesium in liquid and/or a solid matter, wherein thehydrophilic resin composition comprises a hydrophilic resin and a metalferrocyanide compound; the hydrophilic resin is at least one selectedfrom the group consisting of a hydrophilic polyurethane resin, ahydrophilic polyurea resin, and a hydrophilic polyurethane-polyurearesin each having a hydrophilic segment, further each having, in themain chain and/or a side chain in the structure thereof, a tertiaryamino group, and each obtained by reacting an organic polyisocyanate, ahigh molecular weight hydrophilic polyol and/or polyamine being ahydrophilic component, and a compound having at least one activehydrogen-containing group and at least one tertiary amino group in thesame molecule; and the metal ferrocyanide compound is dispersed in thehydrophilic resin composition in a ratio of at least 1 to 200 mass partsrelative to 100 mass parts of the hydrophilic resin.
 19. A hydrophilicresin composition for removing radioactive iodine and radioactive cesiumexhibiting a function capable of immobilizing both of radioactive iodineand radioactive cesium in liquid and/or a solid matter, wherein thehydrophilic resin composition comprises a hydrophilic resin and a metalferrocyanide compound; the hydrophilic resin is a resin having ahydrophilic segment, having, in the molecular chain, a tertiary aminogroup and a polysiloxane segment, and formed from, as a part of a rawmaterial, a polyol having at least one tertiary amino group or apolyamine having at least one tertiary amino group and a compound havingat least one active hydrogen-containing group and a polysiloxane segmentin the same molecule, the resin being insoluble to water and hot water;and the metal ferrocyanide compound is dispersed in the hydrophilicresin composition in a ratio of at least 1 to 200 mass parts relative to100 mass parts of the hydrophilic resin.
 20. A hydrophilic resincomposition for removing radioactive iodine and radioactive cesiumexhibiting a function capable of immobilizing both of radioactive iodineand radioactive cesium in liquid and/or a solid matter, wherein thehydrophilic resin composition comprises a hydrophilic resin and a metalferrocyanide compound; the hydrophilic resin is at least one selectedfrom the group consisting of a hydrophilic polyurethane resin, ahydrophilic polyurea resin, and a hydrophilic polyurethane-polyurearesin each having a hydrophilic segment, each having, in the main chainand/or a side chain in the structure thereof, a tertiary amino group anda polysiloxane segment, and each obtained by reacting an organicpolyisocyanate, a high molecular weight hydrophilic polyol and/orpolyamine being a hydrophilic component, a compound having at least oneactive hydrogen-containing group and at least one tertiary amino groupin the same molecule, and a compound having at least one activehydrogen-containing group and a polysiloxane segment in the samemolecule; and the metal ferrocyanide compound is dispersed in thehydrophilic resin composition in a ratio of at least 1 to 200 mass partsrelative to 100 mass parts of the hydrophilic resin.
 21. The hydrophilicresin composition for removing radioactive iodine and radioactive cesiumaccording to claim 17, wherein the hydrophilic segment of thehydrophilic resin is a polyethylene oxide segment.
 22. The hydrophilicresin composition for removing radioactive iodine and radioactive cesiumaccording to claim 17, wherein the metal ferrocyanide compound is acompound represented by the following general formula (1):A_(x)M_(y)[Fe(CN)₆]  (1) [in the formula, A is any one selected from K,Na, and NH₄, M is any one selected from Ca, Mn, Fe, Co, Ni, Cu, and Zn,x and y satisfy an equation x+ny=4 (x is an integer from 0 to 3), and nrepresents a valence number of M].